Treatment of cancers and hematopoietic stem cell disorders privileged by cxcl12-cxcr4 interaction

ABSTRACT

Methods are presented for treating cancers and hematopoietic stem cell disorders, comprising administering to a subject with a cancer or hematopoietic stem cell disorder who is receiving a treatment regimen, a heparin derivative capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, wherein the cancer or hematopoietic stem cell disorder is one in which interaction of CXCL12 with CXCR4 privileges the cancer or disordered HSCs against therapeutic intervention. In preferred embodiments, the heparin derivative is a substantially 2-0, 3-O-desulfated heparin derivative.

1. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Nos. 62/277,360, filed Jan. 11, 2016; 62/181,513, filed Jun. 18, 2015; and 62/117,409, filed Feb. 17, 2015, the disclosures of which are incorporated herein by reference in their entireties for all purposes.

2. BACKGROUND

Animal models have long predicted that heparin and various heparin derivatives would enhance the efficacy of chemotherapy in the treatment of human cancers. Tani and colleagues, for example, reported that heparin enhances potency of gemcitabine in a pancreatic cancer model (Tani et al., Abstract 4175, Cancer Res. 70(8) (Suppl. 1) (2010)). WO 2012/106379 analogously reports that a substantially non-anticoagulating 2-O, 3-O-desulfated heparin derivative, “ODSH”, improves the efficacy of a chemotherapy regimen that includes gemcitabine in a standard tumor xenograft animal model of human pancreatic cancer.

However, the animal models have proven to be poor at predicting efficacy in human patients, and convincing evidence is sparse that adding heparin or various heparin derivatives enhances efficacy of standard antineoplastic treatment regimens.

For example, despite a wealth of data from both preclinical animal models and early human phase II trials that had suggested that low molecular weight heparin (“LMWH”) significantly prolongs survival in a wide variety of cancers in patients without venous thromboembolism, Maraveyas and colleagues reported in 2012 that adding the LMWH dalteparin to gemcitabine provided no statistically significant improvement in survival in advanced pancreatic cancer in a properly powered trial (Maraveyas et al., Eur. J. Cancer 48:1283-1292 (2012)). In a contemporaneous phase II randomized study, dalteparin could not be shown to improve outcome in ovarian cancer patients being treated with a standard chemotherapy regimen (Elit et al., Thromb Res. 130(6):894-900 (2012)). A few months earlier, van Doormaal et al. had analogously reported that adding the LMWH nadroparin to existing standard of care protocols in patients with advanced prostate, lung, or pancreatic cancer provided no statistically significant survival benefit (van Doormaal et al., J. Clin. Oncol. 29:2071-2076 (2011)).

Similarly, despite the evidence from animal models that ODSH could enhance the efficacy of chemotherapeutic regimens in treatment of pancreatic cancer, no statistically significant benefit in progression-free survival or overall survival was observed in a later human clinical trial testing addition of ODSH to the standard-of-care chemotherapy regimen of gemcitabine plus nab-paclitaxel in patients with metastatic adenocarcinoma of the pancreas (Clinical Trial.gov NCT01461915).

Despite continuing advances in treating cancer, there is still a need in the art for more effective treatments, and for treatments that have fewer side effects.

Myelodysplastic syndromes (“MDS”) represent a spectrum of clonal hematopoietic stem cell disorders characterized by progressive bone marrow failure and increased risk of progression to acute myeloid leukemia (“AML”, also known as “acute myelogenous leukemia”). The International Prognostic Scoring System (“IPSS”) is widely used to identify patients with high risk features based on the severity of their cytopenias, bone marrow myeloblast percentage, and cytogenetic abnormalities. For patients with MDS, allogeneic hematopoietic stem cell transplantation remains the only curative treatment option. However, MDS is a disease of older individuals, with fewer than 5 percent of cases occurring in patients younger than 50 years and the majority being diagnosed at an age over 70 years. Because of age, comorbidities, and other factors, less than 10 percent of all MDS patients are able to proceed to potentially curative allogeneic hematopoietic stem cell transplantation.

Hypomethylating agents are considered standard first line therapy for patients with higher risk disease. Unfortunately, these agents are not curative and only achieve remission in approximately 20-30 percent of patients, with a median duration of response of 8-10 months. Outcomes after hypomethylating agents are poor. There remains an unmet need for better treatment of myelodysplasias.

3. SUMMARY

It has now been discovered that heparin derivatives (collectively, “heparinoids”) that are capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4 (“CXCL12-interacting heparinoids”) can increase the efficacy of antineoplastic regimens against a selected subset of cancers, those in which interaction of CXCL12 with CXCR4 privileges the cancer against therapeutic intervention. In certain embodiments, the cancers are those in which neoplastic cells, including but not limited to cancer stem cells, migrate to and/or reside in one or more anatomic sites, such as the bone marrow, that provide protection from the antineoplastic regimen. In certain embodiments, the cancers are those in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on tumor cells.

Moreover, because the bone marrow niche upregulates production of CXCR4 and CXCR12 in disorders of hematopoietic stem cells (“HSC”s), and this upregulation is believed to promote survival of the disordered HSCs, heparinoids that are capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4 can increase the efficacy of agents, such as hypomethylating agents, such as azacitidine, that are used to treat such HSC disorders, such as MDS.

Thus, in a first aspect, methods of treating cancer are provided.

The methods comprise administering to a subject receiving an antineoplastic treatment regimen a heparin derivative capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, wherein the cancer is one in which interaction of CXCL12 with CXCR4 privileges the cancer against therapeutic intervention. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen.

In certain embodiments, the cancer is one in which neoplastic cells, such as cancer stem cells, migrate to and/or reside in anatomic sites that are capable of protecting the neoplastic cells from the antineoplastic treatment regimen. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to mobilize neoplastic cells from the anatomic site that is capable of protecting the neoplastic cells from the antineoplastic treatment regimen. Typically, the amount is effective to mobilize neoplastic cells from the bone marrow.

In certain embodiments, the cancer is one in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on tumor cells. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to reduce CXCL12-CXCR4 interaction. In certain embodiments, the heparin derivative is administered in an amount effective to reduce tumor-specific immunosuppression.

In a related aspect, improved methods are provided for treating cancers with an antineoplastic treatment regimen, wherein the cancer is one in which interaction of CXCL12 with CXCR4 privileges the cancer against therapeutic intervention, the improvement comprising further administering a heparin derivative that is capable of inhibiting, reducing, abrogating, or otherwise interfering with the binding of CXCL12 to CXCR4, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen.

In certain embodiments, the cancer is one in which neoplastic cells migrate to and/or reside in anatomic sites capable of protecting the neoplastic cells from an antineoplastic treatment regimen, the improvement comprising further administering a heparin derivative that is capable of inhibiting, reducing, abrogating, or otherwise interfering with the binding of CXCL12 to CXCR4, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to mobilize neoplastic cells from the anatomic site that is capable of protecting the neoplastic cells from the antineoplastic treatment regimen. Typically, the amount is effective to mobilize neoplastic cells from the bone marrow.

In certain embodiments, the cancer is one in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on tumor cells, the improvement comprising further administering a heparin derivative that is capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to reduce CXCL12-CXCR4 interaction. In certain embodiments, the heparin derivative is administered in an amount effective to reduce tumor-specific immunosuppression.

In certain embodiments, the cancer is a carcinoma. In certain embodiments, the cancer is lung cancer. In certain other embodiments, the lung cancer is non-small-cell lung cancer. In certain other embodiments, the cancer is a hematologic cancer. In certain embodiments, the hematologic cancer is leukemia. In certain other embodiments, leukemia is acute myeloid leukemia (AML). In certain embodiments the AML is primary AML. In certain other embodiments, the AML is secondary AML.

In another aspect, methods of treating disorders of hematopoietic stem cells are provided. The methods comprise administering to a subject receiving a treatment regimen for a hematopoietic stem cell disorder a heparin derivative capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the treatment regimen.

In certain embodiments, the hematopoietic stem cell disorder is one in which the disordered HSC cells migrate to and/or reside in one or more anatomic sites that provide protection from the treatment regimen, such as the bone marrow. In certain embodiments, the hematopoietic stem cell disorder is one in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on the disordered HSCs.

In some embodiments, the disordered HSC cells have abnormal karyotype. In some of these embodiments, the disordered HSC cells are pre-cancerous stem cells.

In certain embodiments, the hematopoietic stem cell disorder is MDS. In certain embodiments, the disorder is newly diagnosed MDS. In certain embodiments, the disorder is recurrent or refractory MDS.

In certain embodiments, the subject has been diagnosed with MDS and symptomatic anemia. In some of these embodiments, the subject has hemoglobin levels less than 10.0 g/dL or requires red blood cell transfusion. In certain embodiments, the subject has been diagnosed with MDS and thrombocytopenia. In some of these embodiments, the subject has a history of two or more platelet counts less than 50,000/μL or a significant hemorrhage requiring platelet transfusions. In certain embodiments, the subject has been diagnosed with MDS and neutropenia. In some of these embodiments, the subject has two or more absolute neutrophil counts less than 1,000/μL. In certain embodiments, the subject has been diagnosed with MDS and has an IPSS score of INT-1 or higher prior to treatment.

In certain embodiments, the treatment regimen is hypomethylation therapy.

In certain embodiments, the subject has undergone greater than or equal to 4 cycles of treatment of a hypomethylating agent without response, or have documented disease progression after prior response to a hypomethylating therapy.

In certain embodiments, the hypomethylation agent is decitabine.

In certain embodiments, the hypomethylation agent is azacitidine.

In certain embodiments, the azacitidine is administered to the subject intravenously.

In certain embodiments, the azacitidine is administered at a dosage range of 5-500 mg/m².

In certain embodiments, the azacitidine is administered at 75 mg/m² as a 15 minute intravenous infusion daily on days 1 through 5 of each 28-day cycle.

In certain embodiments, the azacitidine is administered for up to 6 cycles.

In certain embodiments, the heparin derivative is administered to the subject intravenously.

In certain embodiments, the heparin derivative is administered continuously.

In certain embodiments, the heparin derivative is administered as a bolus injection.

In certain embodiments, the heparin derivative is administered as a bolus injection followed by continuous administration.

In certain embodiments, the heparin derivative is administered subcutaneously.

In certain embodiments, the heparin derivative is administered at a dosage range of 0.01 mg/kg to 100 mg/kg.

In certain embodiments, the heparin derivative is administered as a 4 mg/kg bolus on Day 1 followed by a continuous intravenous infusion of 0.25 mg/kg/hr for days 1 through 5 of each 28-day cycle.

In certain embodiments, the heparin derivative is administered for up to 6 cycles.

In certain embodiments, the heparin derivative is administered prior to the antineoplastic treatment.

In certain embodiments, the heparin derivative is administered concurrently with the antineoplastic treatment.

In certain embodiments, the heparin is administered prior to and concurrently with the antineoplastic treatment.

In certain embodiments, the disorder is one in which neoplastic cells or pre-neoplastic cells, such as cancer stem cells, migrate to and/or reside in anatomic sites that are capable of protecting the neoplastic or pre-neoplastic cells from the antineoplastic treatment regimen. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to mobilize neoplastic cells from the anatomic site that is capable of protecting the neoplastic cells or pre-neoplastic cells from the antineoplastic treatment regimen. Typically, the amount is effective to mobilize neoplastic cells from the bone marrow.

In certain embodiments, the amount of the heparin derivative is effective to cause a complete response or a near complete response rate in the subject.

In certain embodiments, the amount is effective to cause a partial response rate in the subject.

In certain embodiments, performing the methods will determine the tolerability and toxicities of combination treatment of azacitidine and azacitidine and heparin derivatives.

In certain embodiments, performing the methods will determine the event free, progression free, disease free, 10 year survival and overall survival of subjects treated with azacitine and azacitidine and heparin derivatives.

In certain embodiments, performing the methods will determine hematologic improvement evaluated by absolute neutrophil count, platelet and red blood cell response.

In certain embodiments, performing the methods will determine cytogenetic response as evaluated by reversion to normal karyotype.

In certain embodiments, the disorders are hematologic disorders.

In certain embodiments, the disorders are those in which cells are pre-neoplastic cells.

In certain embodiments, the disorder is myelodysplastic syndrome (MDS).

In certain embodiments, the disorder is newly diagnosed MDS.

In certain embodiments, the disorder is recurrent or refractory MDS.

In certain embodiments, the disorders are those in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on the cells.

In certain embodiments, the anti-neoplastic regiment is treatment with a hypomethylating agent.

In certain embodiments, the hypomethylating agent is azacitidine.

4. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the chemical formula of the ATIII-binding pentasaccharide sequence of USP heparin (also known as “unfractionated heparin”, or “UFH”) and the comparable sequence of a 2-O, 3-O-desulfated heparin derivative prepared by cold alkaline hydrolysis of UFH.

FIGS. 2A-2C are photomicrographs of serial bone marrow biopsies of a patient with acute myeloid leukemia (“AML”, also known as acute myelogenous leukemia) treated with an ODSH pharmaceutical composition (“CX-01”) in combination with cytarabine and idarubicin, as described in Example 1. FIG. 2A shows bone marrow prior to treatment. FIG. 2B shows marrow at day 14 of treatment. FIG. 2C shows day 28 marrow.

FIG. 3 compares the complete response rate (CR) observed in the clinical trial described in Example 1 to historical control (indicated by asterisk).

FIG. 4 shows the concentration-dependent inhibition of CXCR4 binding to SDF1α (CXCL12) by ODSH in an in vitro binding assay.

5. DETAILED DESCRIPTION

5.1. Overview of Experimental Observations

Data from animal models have long suggested that heparin and certain heparin derivatives can enhance the efficacy of antineoplastic treatment regimens, such as chemotherapy. Despite sporadic anecdotal reports in human patients, however, there is sparse evidence of statistically significant clinical enhancement in human cancer patients.

For example, the substantially non-anticoagulant 2-O, 3-O desulfated heparin derivative, ODSH (see FIG. 1), was shown to sensitize cancer cells to chemotherapy in animal models of human pancreatic adenocarcinoma (WO 2012/106379). When later tested in a human clinical trial (ClinicalTrials.gov identifier NCT01461915), however, addition of ODSH to the chemotherapy regimen did not provide a statistically significant increase in progression-free survival or overall survival in patients with metastatic adenocarcinoma of the pancreas.

Although unable to prolong progression-free survival or overall survival in patients with metastatic pancreatic cancer, ODSH was found, unexpectedly, to attenuate the myelosuppressive side effects of the gemcitabine plus nab-paclitaxel chemotherapy regimen (U.S. Pat. No. 8,734,804, incorporated herein by reference in its entirety).

To confirm the myeloprotective effects of ODSH, a second clinical trial was initiated in a different cancer, acute myeloid leukemia (“AML”, also known as acute myelogenous leukemia), treated with a different myelosuppressive chemotherapeutic regimen, idarubicin plus cytarabine (ClinicalTrials.gov identifier: NCT02056782).

As described in detail in Example 1, below, ODSH significantly attenuated the myelosuppressive side effects of the idarubicin+cytarabine anti-AML chemotherapy regimen, as expected. In addition, however, and unexpectedly given prior failure of ODSH to improve response to chemotherapy in the pancreatic cancer trial, ODSH also improved the efficacy of the chemotherapy treatment: 11 out of 12 patients (92%) treated with both ODSH and idarubicin plus cytarabine, including two patients who received an incomplete course of chemotherapy (3 and 5 days respectively), had a morphologic complete remission at the end of a single induction cycle, higher than would otherwise have been expected. All 11 patients with primary AML achieved a complete remission at the end of a single induction cycle. Furthermore, 10 of the 12 patients remain in complete remission 5-13 months after having been enrolled in the study.

Thus, it has now been discovered that ODSH can increase the efficacy of antineoplastic regimens against a selected subset of cancers, notwithstanding the fact that ODSH cannot increase the efficacy of antineoplastic regimens against various other cancers.

As described in Example 2, serial bone marrow biopsies drawn from one of the patients treated with ODSH, cytarabine, and idarubicin in the AML clinical trial unexpectedly showed significant depletion of cellular elements in addition to the expected depletion of leukemic cells. FIG. 2A shows bone marrow prior to treatment, demonstrating that the marrow is packed with leukemia cells. FIG. 2B shows marrow at Day 14 of the induction cycle, demonstrating elimination of most normal bone marrow cells as well as leukemia cells. FIG. 2C shows day 28 marrow, with no evidence of leukemic cells and restoration of normal bone marrow appearance and function.

Without intending to be bound by theory, the unexpected clearance of cells from the marrow seen in the Day 14 biopsy suggests that the increased remission rate observed in the AML clinical trial can be attributed to ODSH-mediated mobilization of leukemic cells from the marrow into the peripheral circulation, where they became vulnerable to the infusions of cytarabine and idarubicin. Retention of leukemic cells in the bone marrow is known to make them more resistant to chemotherapy (Hope et al., Nat. Immunol. 5:738-742 (2004)). The recovery of the marrow by Day 28 demonstrates further that the ODSH-mediated flushing of cells from the marrow does not adversely affect the ability of the marrow to repopulate and support multi-lineage hematopoiesis. Indeed, the accelerated recovery of platelet and white cell count, consistent with observations from the previous trial in pancreatic cancer, demonstrates that the marrow microenvironments required for thrombopoiesis, erythropoiesis, and granulopoiesis remain healthy.

CXCL12, also known as Stromal Cell Derived Factor-1 or SDF-1, was originally described as a CXC chemokine produced locally within the bone marrow compartment to provide a homing signal for hematopoietic stem cells (“HSC”s). CXCL12 is the ligand for the CXCR4 receptor on the surface of HSCs; ligation of CXCR4 by CXCL12 is known to promote stem cell survival, proliferation, migration, and chemotaxis (see, e.g., Lapidot et al., Leukemia 16(10):1992-2003 (2002)). It has also been reported that the CXCR4 receptor is prominently expressed on the cell membrane of many cancer cells, particularly cancer stem cells (Yu et al., Gene 374:174-9 (2006); Cojoc et al., Oncotargets & Therapy 6:1347-1361(2013)), and that the CXCL12/CXCR4 interaction may mediate migration of cancer cells to anatomic sites that produce CXCL12 (Wald et al., Theranostics 3:26-33 (2013); Cojoc et al., supra).

To determine whether the ODSH-mediated mobilization of cells from the bone marrow observed in the AML clinical trial could be attributed to abrogation of, or interference with, the binding of CXCL12 to CXCR4, an in vitro inhibition assay was performed. Results are reported in Example 3 and FIG. 4.

As shown in FIG. 4, ODSH inhibits binding of CXCL12 (SDF-1) to CXCR4 in a concentration-dependent fashion, with an IC₅₀ of 0.010 μg/ml. This inhibitory concentration is well within the range of plasma concentrations expected to have been achieved in the AML trial: as detailed in Example 1, patients were administered a bolus of 4 mg/kg followed by a continuous intravenous infusion at a dose of 0.25 mg/kg/hr for a total of 7 days; an earlier phase I pharmacokinetics study had demonstrated that a bolus of 8 mg/kg followed by continuous intravenous infusion of 0.64 to 1.39 mg/kg/h provides a maximum mean plasma level of about 170 μg/ml, and steady state concentrations of about 40 μg/mL (Rao et al., Am. J. Physiol. Cell Physiol. 299:C997-C110 (2010)). These concentrations were not significantly anticoagulating.

Without intending to be bound by theory, the discovery that ODSH inhibits the binding of CXCL12 to CXCR4 identifies the subset of cancers for which ODSH can increase therapeutic efficacy of antineoplastic treatment regimens as that subset in which interaction of CXCL12 with CXCR4 privileges the cancer against therapeutic intervention. In certain embodiments, the cancers are those in which neoplastic cells, including but not limited to cancer stem cells, migrate to and/or reside in one or more anatomic sites that provide protection from the antineoplastic regimen, such as the bone marrow. In certain embodiments, the cancers are those in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on tumor cells.

In addition, the discovery that ODSH inhibits binding of CXCL12 to CXCR4 identifies the subset of heparin derivatives capable of effecting this improvement in therapeutic efficacy as that subset of heparin derivatives that are capable of inhibiting, reducing, abrogating or otherwise interfering with the interaction of CXCL12 with CXCR4, including those heparin derivatives that are capable of binding to CXCL12 and/or CXCR4.

Moreover, because the bone marrow niche upregulates production of CXCR4 and CXCR12 in myelodysplasias, and this upregulation is believed to promote survival of aberrant hematopoietic stem cells in MDS, heparin derivatives that are capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4 can increase the efficacy of hypomethylating agents, such as azacitidine, and of other chemotherapeutic agents that are used to treat MDS.

5.2. Methods of Treatment

5.2.1. Methods of Treating Cancer

Accordingly, in a first aspect, methods of treating cancer are provided.

The methods comprise administering to a subject receiving an antineoplastic treatment regimen a heparin derivative capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, wherein the cancer is one in which interaction of CXCL12 with CXCR4 privileges the cancer against therapeutic intervention. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen.

In certain embodiments, the cancer is one in which neoplastic cells, such as cancer stem cells, migrate to and/or reside in anatomic sites that are capable of protecting the neoplastic cells from the antineoplastic treatment regimen. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to mobilize neoplastic cells from the anatomic site that is capable of protecting the neoplastic cells from the antineoplastic treatment regimen. Typically, the amount is effective to mobilize neoplastic cells from the bone marrow.

In certain embodiments, the cancer is one in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on tumor cells. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to reduce CXCL12-CXCR4 interaction. In certain embodiments, the heparin derivative is administered in an amount effective to reduce tumor-specific immunosuppression.

In a related aspect, improved methods are provided for treating cancers with an antineoplastic treatment regimen, wherein the cancer is one in which interaction of CXCL12 with CXCR4 privileges the cancer against therapeutic intervention, the improvement comprising further administering a heparin derivative that is capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen.

In certain embodiments, the cancer is one in which neoplastic cells migrate to and/or reside in anatomic sites capable of protecting the neoplastic cells from an antineoplastic treatment regimen, the improvement comprising further administering a heparin derivative that is capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to mobilize neoplastic cells from the anatomic site that is capable of protecting the neoplastic cells from the antineoplastic treatment regimen. Typically, the amount is effective to mobilize neoplastic cells from the bone marrow.

In certain embodiments, the cancer is one in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on tumor cells, the improvement comprising further administering a heparin derivative that is capable of inhibiting, reducing, abrogating or otherwise interfering with the binding of CXCL12 to CXCR4, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to reduce CXCL12-CXCR4 interaction. In certain embodiments, the heparin derivative is administered in an amount effective to reduce tumor-specific immunosuppression.

5.2.1.1. Selected Cancers

5.2.1.1.1. Cancers Characterized by Migration to Privileged Anatomic Sites

In certain embodiments of the methods described herein, the cancer is selected from those in which neoplastic cells migrate to and/or reside in anatomic sites that are capable of protecting the neoplastic cells from an antineoplastic treatment regimen (hereinafter, “privileged anatomic sites”). In various embodiments, the privileged anatomic site is selected from the group consisting of bone marrow, liver, and brain. In typical embodiments, the privileged anatomic site is the bone marrow.

In some embodiments, the cancer is a hematologic cancer. In various such embodiments, the cancer is selected from the group consisting of acute myeloid leukemia (“AML”, also known as acute myelogenous leukemia, or “AML”), acute lymphoblastic leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, and acute monocytic leukemia.

In some embodiments, the cancer to be treated is a cancer having substantial potential to metastasize to the bone marrow. In various of these embodiments, the cancer is selected from the group consisting of prostate cancer, breast cancer, lung cancer and melanoma, all of which show high rates of metastasis to the bone and can home into the niche occupied by HSCs (see, e.g., Kaplan et al., Cancer Metastasis Rev. 25(4):521-9 (2006), incorporated herein by reference in its entirety). In certain embodiments, the cancer is kidney cancer, thyroid cancer, or neuroblastoma. In certain embodiments, the cancer to be treated is head and neck cancer, esophagus cancer, stomach cancer, colorectal cancer, or sarcoma.

In some embodiments, the cancer to be treated is selected from the group consisting of metastatic prostate cancer, metastatic lung cancer, including metastatic non-small cell lung cancer, metastatic breast cancer, and metastatic neuroblastoma.

In some embodiments, the cancer to be treated is lung cancer.

In certain lung cancer embodiments, the cancer is small cell lung cancer. In other embodiments, the lung cancer is non-small cell lung cancer (“NSCLC”).

In certain NSCLC embodiments, the NSCLC is locally advanced. In certain embodiments, the NSCLC is inoperable. In certain embodiments, the NSCLC is locally advanced and inoperable. In certain embodiments, the non-small cell lung cancer is Stage IIIB NSCLC. In some embodiments, the NSCLC is oligometastatic stage IV non-small cell lung cancer. In some embodiments, the NSCLC is being treated with radiation therapy and chemotherapy.

In some embodiments, the cancer to be treated is characterized by the presence of post-treatment minimal residual disease. “Minimal residual disease” generally refers to cancer cells that persist after antineoplastic therapy, and whose presence is correlated with relapse of the disease. Without intending to be bound by theory, the minimal residual disease state is attributed to persistence of cancer stem cells, often resident in privileged anatomic sites, and which are more resistant to therapeutic treatments and have the capacity to give rise to variant cancer cell types found in the particular cancer. By escaping effect of cancer treatments, the cancer stem cells can cause relapse and metastasis by producing new cancer cell types. In particular, cancers with minimal residual disease in the bone marrow, liver, brain, or other similar tissues are appropriate cancers to be treated according to the methods described herein.

In certain embodiments, cancers with minimal residual disease states are selected from the group consisting of breast cancer, glioblastoma, small cell lung cancer, non-small cell lung cancer, prostate cancer, primary acute myeloid leukemia, secondary acute myeloid leukemia, refractory acute myeloid leukemia, and chronic myelogenous leukemia. In some embodiments, any cancer with minimal residual disease in the bone marrow or like tissues that protect neoplastic cells from antineoplastic treatment following initial antineoplastic treatment is an appropriate cancer to be treated according to the methods described herein.

5.2.1.1.2. Cancers Characterized by Stromal Expression of CXCL12

In certain embodiments, the cancer is selected from those in which stromal expression of CXCL12 protein exerts a prosurvival influence on tumor cells.

In certain embodiments, the cancer is selected from adenocarcinomas. In certain embodiments, the cancer is selected from primary and metastatic carcinomas. In various embodiments, the cancer is selected from prostate, colorectal, breast, ovarian, bladder, lung (including small cell lung cancer and non-small cell lung cancer), and hepatocellular carcinoma.

5.2.1.2. Antineoplastic Treatment Regimens

In the methods described herein, the antineoplastic treatment regimen is any antineoplastic treatment regimen appropriate for the cancer being treated.

In some embodiments, the treatment regimen includes chemotherapy. In some embodiments, the treatment regimen includes radiation therapy. In some embodiments, the treatment regimen includes antibody therapy. In some embodiments, the treatment regimen includes therapy targeted to mutant enzymes, such as mutated kinases. In some embodiments, the treatment regimen includes immunotherapy, such as immunotherapy with a checkpoint inhibitor.

In the methods provided herein, the antineoplastic treatment regimen can be myelosuppressive or non-myelosuppressive.

Myelosuppressive antineoplastic treatment regimens include those that reduce one or more of platelet count, red blood cell count, white blood cell count, and particularly, neutrophil count. In certain embodiments, the myelosuppressive antineoplastic treatment regimen is capable of causing a grade 1, grade 2, grade 3, or grade 4 thrombocytopenia when administered without adjunct administration of a CXCL12-interacting heparinoid. In some embodiments, the myelosuppressive antineoplastic treatment regimen is capable of causing a grade 1, grade 2, grade 3, or grade 4 neutropenia when administered without adjunct administration of a CXCL12-interacting heparinoid.

In some embodiments, the myelosuppressive antineoplastic treatment regimen includes administration of one or more of an alkylating agent, antimetabolite, anthracyclines, topoisomerase inhibitors or mitotic inhibitors.

In some embodiments, the myelosuppressive antineoplastic treatment regimen includes administration of one or more of venetoclax, decitabine, LY573636, aldesleukin, bortezomib, ixazomib, tipifarnib, panobinostat, pracinostat, clorfarabine, alvocidib, lenolidamide, dasatinib, volasertib, sorafenib, CP-351, vosaroxin, etoposide, mitoxantrone, guadecitabine, gemtuzumab ozogamicin, SGN-CD33A, BI 836858, AGS67E, arsenic trioxide, vorinostat, binimetinib, trametinib, BVD-523, E6201, vyxeos, AZD1775, 8-chloro-adenosine, cladribine, flutarabine, capecitidine, pomalidomide, erwinaze, treosulfan, alisertib, gedatolisib, ruxolitinib, LY2606368, OXi4503, gliteritinib, sunitinib, lestaurtinib, midostaurin, quizartinib, crenolanib, pacritinib, AKN-028, FLX925 or E6201.

In some embodiments, the myelosuppressive antineoplastic treatment regimen includes administration of one or more of a FMS-related tyrosine kinase-3 inhibitor, a tyrosine kinase inhibitor, a proteasome inhibitor, a histone deacetylase inhibitor, a CD-33 inhibitor, a MEK inhibitor, a purine analog, an asparaginase, an mTOR inhibitor or an Aurora Kinase inhibitor.

In particular embodiments, the antineoplastic treatment regimen is a non-myelosuppressive treatment regimen. As used herein, “non-myelosuppressive” treatment regimen refers to a treatment regimen that does not substantially reduce one or more of platelet count, red blood cell count, white blood cell count, and neutrophil count when administered without adjunct administration of a CXCL12-interacting heparinoid. In preferred embodiments, the non-myelosuppressive treatment regimen does not cause a grade 1, grade 2, grade 3, or grade 4 thrombocytopenia when administered without adjunct administration of a CXCL12-interacting heparinoid. In certain embodiments, the non-myelosuppressive treatment regimen does not cause a grade 1, grade 2, grade 3, or grade 4 neutropenia when administered without adjunct administration of a CXCL12-interacting heparinoid.

In some embodiments, the non-myelosuppressive antineoplastic treatment regimen includes administration of one or more of a kinase inhibitor, a VEGF inhibitor, a VEGFR inhibitor, a VEGFR2 inhibitor, a PDGFR inhibitor, a Src family kinase inhibitor, a hedgehog inhibitor, a retinoid X receptor activator, a histone methyltransferase inhibitor, a BCL2 inhibitor, an AKT inhibitor, a CXCR4 inhibitor, an mTOR inhibitor, an Mdm2 antagonist, an Mdm2 inhibitor, a CD25 inhibitor, a CD47 inhibitor, an IL-3R inhibitor, a BCR-Abl inhibitor, a HSP90 inhibitor, an HGF inhibitor, a MET inhibitor and a bromodomain and extra-terminal domain (BET) inhibitor and a BRD4 inhibitor.

In some embodiments, the non-myelosuppressive treatment regimen includes administration of one or more of crizotinib, seliciclib, afatinib, aldesleukin, alemtuzumab; axitinib, belinostat, bosutinib, brentuximab vedotin, carfilzomib, ceritinib, dabrafenib, dasatinib, everolimus, ibritumomab tiuxetan, ibrutinib, sorafenib, idelalisib, ipilimumab, nilotinib, obinutuzumab, ofatumumab, panitumumab, pembrolizumab, pertuzumab, ponatinib, ramucirumab, regorafenib, romidepsin, sipuleucel, temsirolimus, tositumomab, trametinib, vandetanib, vemurafenib, vismodegib, vorinostat, ziv-aflibercept, cabozantinib, selinexnor, PF-4449913, erismodegib, GO-203-2C, thioridazine, nivolumab. bexarotene, EPZ-5676, ABT-199, GSK2141795, entospletinib, TAK-659, CPI-613, B1-8040, LY2510924, plerixafor, mozobil, OCV-501, pacritinib, eltrombopag, promacta, revolade, nintedanib, vargatef, rapamycin, MEN1112, ipilimumab, idasanutlin, R06839921, AMG-232, ADCT-301, KHK2823, CWP232291, SL-401, CC-90002, GSK2879552, lirilumab, BGB324, OTX-015, TEN-010, I-BET 762, CPI-203, CPI-0610, AG-120, AG-221 or IDH305.

In some embodiments, the non-myelosuppressive treatment regimen includes administration of one or more of bleomycin, vincristine, prednisolone, and gallium nitrate.

In some embodiments, the non-myelosuppressive antineoplastic treatment regimen comprises administration of a non-myelosuppressive targeted therapeutic agent or an immunostimulatory or immunomodulatory therapeutic agent. As used herein, a “non-myelosuppressive targeted therapeutic” refers to a therapeutic agent that targets the cancer cell with sufficient specificity to not have myelosuppressive effects.

A “non-myelosuppressive immunostimulatory therapeutic” refers to a therapeutic agent that stimulates immune activity against the cancer cells, such as by reducing suppression of effector immune cells or activating immune cells that result in a therapeutic response against the cancer cells.

In some embodiments, the immunostimulatory therapeutic agent comprises one or more checkpoint inhibitors. In certain embodiments, the checkpoint inhibitor is a monoclonal antibody. In certain embodiments, the monoclonal antibody is selected from an anti-CTLA-4 monoclonal antibody, an anti-PD1 monoclonal antibody, an anti-PDL1 monoclonal antibody, and combinations thereof

5.2.2. Methods of Treating Hematopoietic Stem Cell Disorders

In another aspect, methods of treating hematopoietic stem cell disorders are provided.

The methods comprise administering to a subject receiving a treatment regimen for a hematopoietic stem cell disorder a heparin derivative capable of inhibiting binding of CXCL12 to CXCR4. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the treatment regimen.

In certain embodiments, the hematopoietic stem cell disorder is one in which the disordered HSC cells migrate to and/or reside in one or more anatomic sites that provide protection from the treatment regimen, such as the bone marrow. In certain embodiments, the hematopoietic stem cell disorder is one in which stromal cell expression of CXCL12 protein exerts a prosurvival influence on the disordered HSCs. In certain embodiments, the hematopoietic stem cell disorder is one in which stromal cell expression of CXCL12 protein inhibits apoptosis of the disordered HSCs.

In some embodiments, the disordered HSC cells have abnormal karyotype. In some of these embodiments, the disordered HSC cells are pre-cancerous stem cells.

In certain embodiments, the hematopoietic stem cell disorder is myelodysplastic syndrome (“MDS”, also known as “myelodysplasia”). In certain embodiments, the disorder is newly diagnosed MDS. In certain embodiments, the disorder is recurrent or refractory MDS.

In certain embodiments, the subject has been diagnosed with MDS and symptomatic anemia. In some of these embodiments, the subject has hemoglobin levels less than 10.0 g/dL or requires red blood cell transfusion. In certain embodiments, the subject has been diagnosed with MDS and thrombocytopenia. In some of these embodiments, the subject has a history of two or more platelet counts less than 50,000/μL or a significant hemorrhage requiring platelet transfusions. In certain embodiments, the subject has been diagnosed with MDS and neutropenia. In some of these embodiments, the subject has two or more absolute neutrophil counts less than 1,000/μL. In certain embodiments, the subject has been diagnosed with MDS and has an IPSS score of INT-1 or higher prior to treatment.

In typical embodiments, the treatment regimen for myelodysplasia is hypomethylation therapy. In certain embodiments, the subject has not undergone prior treatment with hypomethylation therapy. In other embodiments, the subject has undergone prior treatment with a hypomethylating agent. In various of these embodiments, the subject has undergone 1 prior treatment, 2 prior treatments, 3 prior treatments, or even 4 prior treatments with a hypomethylating agent without complete remission.

In certain embodiments, the hypomethylation agent is decitabine.

In certain embodiments, the hypomethylation agent is azacitidine. In certain azacitidine embodiments, the azacitidine is administered to the subject intravenously. In certain embodiments, the azacitidine is administered at a dosage range of 5-500 mg/m². In certain embodiments, the azacitidine is administered at 75 mg/m² as a 15 minute intravenous infusion daily on days 1 through 5 of each 28-day cycle. In certain embodiments, the azacitidine is administered for up to 6 cycles.

In certain embodiments, the heparin derivative is administered to the subject intravenously. In certain intravenous embodiments, the heparin derivative is administered as a bolus injection. In certain intravenous embodiments, the heparin derivative is administered continuously. In certain intravenous embodiments, the heparin derivative is administered as a bolus injection followed by continuous administration.

In certain embodiments, the heparin derivative is administered as a 4 mg/kg bolus on Day 1 followed by a continuous intravenous infusion of 0.25 mg/kg/hr for days 1 through 5 of each 28-day cycle. In certain embodiments, the heparin derivative is administered for up to 6 cycles. In certain embodiments, the heparin derivative is administered prior to the myelodysplasia treatment regimen. In certain embodiments, the heparin derivative is administered concurrently with the myelodysplasia treatment regimen. In certain embodiments, the heparin is administered prior to and concurrently with the myelodysplasia treatment regimen. In typical embodiments, the myelodysplasia treatment regimen is administration of a hypomethylation agent.

In certain embodiments, the heparin derivative is administered subcutaneously. In certain subcutaneous administration embodiments, the heparin derivative is administered at a dosage range of 0.01 mg/kg to 100 mg/kg.

In certain embodiments, the hematopoietic stem cell disorder is one in which the disordered HSC cells migrate to and/or reside in anatomic sites that are capable of protecting the cells from the treatment regimen. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the treatment regimen. In typical embodiments, the heparin derivative is administered in an amount effective to mobilize HSC cells from the anatomic site that is capable of protecting the disordered HSC cells from the antineoplastic treatment regimen. Typically, the amount is effective to mobilize HSC cells from the bone marrow.

In certain embodiments, the amount of the heparin derivative is effective to cause a complete response or a near complete response rate in the subject. In certain embodiments, the amount is effective to cause a partial response rate in the subject.

In certain embodiments, the methods of treatment are effective to result in improved event free survival as compared to treatment without administration of the heparin derivative. In some embodiments, the methods of treatment are effective to result in improved progression free survival as compared to treatment without administration of the heparin derivative. In some embodiments, the methods of treatment are effective to result in improved disease free survival, 10 year survival, and/or overall survival as compared to treatment without administration of the heparin derivative. In certain embodiments, the methods of treatment result in reversion of the disordered HSC cells to normal karyotype.

5.2.3. Effective Heparin Derivatives

In the methods described herein, the heparin derivative is one capable of inhibiting, reducing, abrogating, or otherwise interfering with the binding of CXCL12 to CXCR4. For convenience, such heparin derivatives are collectively referred to herein as “CXCL12-interacting heparinoids”.

In some embodiments, the CXCL12-interacting heparinoid inhibits binding of CXCL12 to CXCR4 with an IC₅₀ of about 0.05 μg/ml or less, about 0.04 μg/ml or less, about 0.03 μg/ml or less, about 0.02 μg/ml or less, or about 0.01 μg/ml or less in the assay set forth in Example 3. In some embodiments, the CXCL12-interacting heparinoid inhibits binding of CXCL12 to CXCR4 with an IC₉₀ of about 0.7 μg/ml or less, about 0.6 μg/ml or less, about 0.5 μg/ml or less, or about 0.4 μg/ml or less in the assay set forth in Example 3. In some embodiments, the CXCL12-interacting heparinoid is characterized by an IC₅₀ of about 0.01 μg/ml and an IC₉₀ of about 0.5 μg/ml as determined by the method in Example 3. In some embodiments, the CXCL12-interacting heparinoid is capable of inhibiting CXLC12/CXCR4 interaction, as measured by the method set forth in Example 3, which is about the same as an equivalent weight of unfractionated heparin.

In typical embodiments, the CXCL12-interacting heparinoid is capable of effecting at least 20% inhibition of the binding of CXCL12 to CXCR4 in the assay set forth in Example 3 at a concentration that, if achieved in plasma, would not effect substantial anticoagulation. In various embodiments, the CXCL12-interacting heparinoid is capable of effecting at least 25% inhibition of the binding of CXCL12 to CXCR4 in the assay set forth in Example 3 at a concentration that, if achieved in plasma, would not effect substantial anticoagulation. In certain embodiments, the CXCL12-interacting heparinoid is capable of effecting at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60% inhibition of the binding of CXCL12 to CXCR4 in the assay set forth in Example 3 at a concentration that, if achieved in plasma, would not effect substantial anticoagulation. In specific embodiments, the CXCL12-interacting heparinoid is capable of effecting at least 65%, at least 70%, at least 80%, at least 85%, even at least 90%, 91%, 92%, 93%, 94%, 95% inhibition of the binding of CXCL12 to CXCR4 in the assay set forth in Example 3 at a concentration that, if achieved in plasma, would not effect substantial anticoagulation. In particular embodiments, the CXCL12-interacting heparinoid is capable of effecting at least 96%, 97% even at least 98% inhibition of the binding of CXCL12 to CXCR4 in the assay set forth in Example 3 at a concentration that, if achieved in plasma, would not effect substantial anticoagulation.

In various embodiments, the CXCL12-interacting heparinoid is capable of binding to CXCL12 under physiological conditions.

In preferred embodiments, the CXCL12-interacting heparinoid is a derivative of USP heparin (also known as “unfractionated heparin”, “UFH”) that is substantially desulfated at the 2-O position of α-L-iduronic acid (referred to herein as the “2-O position”) and/or 3-O position of D-glucosamine-N-sulfate (6-sulfate) (referred to herein as the “3-O position”). In preferred embodiments, the 2-O, 3-O-desulfated heparin derivative is not substantially desulfated at the 6-0 or N positions.

For purposes of the present disclosure, the percentage desulfation at the 2-O position of a sample of 2-O, 3-O-desulfated heparin derivative (“ODSH”) is defined as the percentage reduction in sulfate functional groups on the 2-O position of the 2-O-sulfo-α-L-iduronic acid residues as compared to the sulfate functional groups on the 2-O positions of the 2-O-sulfo-α-L-iduronic acid residues in a sample of the 6th International Standard for Unfractionated Heparin, NIBSC code 07/328 (“NIBSC standard”). For purposes of the present disclosure, the percentage desulfation at the 3-O position of a sample of ODSH is defined as the percentage reduction in sulfate functional groups on the 3-O position of the 2-deoxy-2-sulfamido-3-O-sulfo-α-D-glucopyranosyl-6-O-sulfate residues as compared to the sulfate functional groups on the 3-O positions of the 2-deoxy-2-sulfamido-3-O-sulfo-α-D-glucopyranosyl-6-O-sulfate residues in a sample of the NIBSC standard.

In some embodiments, the CXCL12-interacting heparinoid is at least 85%, at least 90%, at least 95%, or at least 99% desulfated at the 2-O position. In some embodiments, the CXCL12-interacting heparinoids are at least 85%, at least 90%, at least 95%, or at least 99% desulfated at the 3-O position. In some embodiments, the CXCL12-interacting heparinoids are at least 85%, at least 90%, at least 95%, at least 99% desulfated at the 2-O position and the 3-O position.

For purposes herein, average molecular weight of heparinoids is weight-average molecular weight, Mw, and is determined by size exclusion chromatography according to the USP monograph for Enoxaparin sodium, with USP Heparin MW Calibrant used as an additional calibrant.

In some embodiments, the CXCL12-interacting heparinoids have an average molecular weight from about 2 kDa to about 15 kDa. In some embodiments, the CXCL12-interacting heparinoids have an average molecular weight of at least about 2 kDa, at least about 3 kDa, at least about 4 kDa, at least about 5 kDa, at least about 6 kDa, or at least about 7 kDa. In some embodiments, the CXCL12-interacting heparinoids have an average molecular weight of less than about 15 kDa, less than about 14 kDa, less than about 13 kDa, less than about 12 kDa, less than about 11 kDa, less than about 10 kDa, or less than about 9 kDa. In some embodiments, the average molecular weight of the CXCL12-interacting heparinoid is selected from about 2 kDa, 3 kDa, 4 kDa, 5 kDa, 6 kDa, 7 kDa, 8 kDa, 9 kDa, 10 kDa, 11 kDa, 12 kDa, 13 kDa, 14 kDa, 15 kDa, 16 kDa, 17 kDa, 18 kDa, or a range that includes any of these values as endpoints.

In some embodiments, the substantially 2-O, 3-O desulfated CXCL12-interacting heparinoid for use in the methods described herein are compositions in which the average molecular weight is at least about 8 kDa. In some embodiments, the substantially 2-O, 3-O desulfated CXCL12-interacting heparinoids have an average molecular weight of greater than about 8 kDa. In various embodiments, the substantially 2-O, 3-O desulfated CXCL12-interacting heparinoids have an average molecular weight ranging from about 8 kDa to about 15 kDa. In some embodiments, the substantially 2-O, 3-O desulfated CXCL12-interacting heparinoids for use in the methods described herein have an average molecular weight that ranges in size from about 11 kDa to about 13 kDa.

An exemplary CXCL12-interacting heparinoid is substantially 2-O, 3-O desulfated heparin, referred to herein as ODSH. ODSH for use in the above-described methods can be prepared from bovine or porcine heparin. In an exemplary method of preparing ODSH from porcine heparin, ODSH is synthesized by cold alkaline hydrolysis of USP porcine intestinal heparin, which removes the 2-O and 3-O sulfates, leaving N- and 6-O sulfates on D-glucosamine sugars and carboxylates on α-L-iduronic acid sugars substantially intact (Fryer et al., J. Pharmacol. Exp. Ther. 282: 208-219 (1997), incorporated herein by reference in its entirety). Using this method, ODSH can be produced with an average molecular weight of about 11.7±0.3 kDa. Additional methods for the preparation of substantially 2-O, 3-O desulfated CXCL12-interacting heparinoids may also be found, for example, in U.S. Pat. Nos. 5,668,118, 5,912,237, and 6,489,311, and WO 2009/015183, the contents of which are incorporated herein in their entirety, and in U.S. Pat. Nos. 5,296,471; 5,969,100; and 5,808,021.

In contrast to unfractionated heparin, ODSH is substantially non-anticoagulating: administered to a subject at a dose that is equivalent in weight to a fully-anticoagulating dose of unfractionated heparin, the clotting time measured in an aPTT assay is no greater than 45 seconds, and typically in the upper range of normal, where normal clotting time ranges from about 27 to 35 seconds. By comparison, unfractionated heparin administered to a subject at a fully anticoagulant dose causes time to clot to range from about 60 to about 85 seconds in an aPTT assay.

Thus, in certain preferred embodiments, the CXCL12-interacting heparinoid is substantially non-anticoagulating. In preferred embodiments, the CXCL12-interacting heparinoid, if administered to a subject at a dose that is weight equivalent to a fully-anticoagulating dose of unfractionated heparin, the clotting time measured in an aPTT assay is no greater than 45 seconds.

Another measure of ODSH's anticoagulant activity is its anti-Xa activity which can be determined in an assay carried out using plasma treated with Russell viper venom. In specific examples, ODSH exhibited less than 9 U of anticoagulant activity/mg in the USP anticoagulant assay (e.g., 7±0.3 U), less than 5 U of anti-Xa activity/mg (e.g., 1.9±0.1 U/mg) and less than 2 U of anti-II_(a) activity/mg (e.g., 1.2±0.1 U/mg) (compared to unfractionated heparin which has an activity of 165-190 U/mg in all three assays; Rao et al., Am. J. Physiol. 299:C97-C110 (2010), incorporated herein by reference in its entirety). Thus, in certain embodiments, the CXCL12-interacting heparinoid exhibits less than 9 U of anticoagulant activity/mg in the USP anticoagulant assay, and/or less than 5 U of anti-Xa activity/mg, and/or less than 2 U of anti-II_(a) activity/mg.

Furthermore, ODSH has a low affinity for anti-thrombin III (Kd˜339 μM or 4 mg/ml vs. 1.56 μM or 22 μg/ml for unfractionated heparin), consistent with the observed low level of anticoagulant activity, measured as described in Rao et al., supra, at page C98. Thus, in certain embodiments, the CXCL12-interacting heparinoid has a low affinity for anti-thrombin III (Kd˜339 μM or 4 mg/ml).

In some embodiments, the CXCL12-interacting heparinoids have no more than 40% of the anticoagulating activity of an equal weight of unfractionated heparin by any one or more of the above-described tests. In some embodiments, the CXCL12-interacting heparinoid has no more than 35%, no more than 30%, no more than 20%, no more than 10%, no more than 9%, no more than 8%, no more than 7%, no more than 6%, no more than 5%, no more than 4%, no more than 3%, no more than 2%, or no more than 1% of the anti-coagulating activity of an equal weight of unfractionated heparin by any one or more of the above-described tests.

In some embodiments, the CXCL12-interacting heparinoid does not trigger platelet activation and does not induce heparin-induced thrombocytopenia (HIT). Platelet activation can be determined using a serotonin release assay, for example as described in U.S. Pat. No. 7,468,358 and Sheridan et al., Blood 67:27-30 (1986), incorporated herein by reference. In some embodiments, the CXCL12-interacting heparinoid is capable of binding platelet factor 4, also referred to as chemokine (C-X-C motif) ligand 4 (CXCL4).

In some embodiments, the CXCL12-interacting heparinoid is a low molecular weight heparin (LMWH). “Low molecular weight heparin” or “LMWH” refers to heparin fragments that have a mean molecular weight of about 4 to about 6 kDa. In some embodiments, the LMWHs have a molecular weight distribution of about 1000 to about 10000. LMWHs are typically made by chemical or enzymatic depolymerization of heparin, generally unfractionated heparin, and can be further purified to select the appropriate size of the LMWH. The LMWH can be prepared using a number of different separation or fractionation techniques known to and used by those of skill in the art, including, for example, gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), ultrafiltration, size exclusion chromatography, and the like.

In certain embodiments, the LMWH is selected from the group consisting of bemiparin, nadroparin, reviparin, enoxaparin, parnaparin, certoparin, dalteparin, tinzaparin, and necuparanib.

In typical embodiments, the CXCL12-interacting heparinoid displays bone marrow cell mobilizing activity, particularly HSC mobilizing activity, more particularly bone marrow-residing cancer cell mobilizing activity. In some embodiments, the CXCL12-interacting heparinoid is characterized by about 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more of the HSC mobilizing activity of an equivalent weight of unfractionated heparin. HSC mobilizing activity can be measured by mobilization of cells having one or more of the marker profiles listed in Table 1 below. In certain embodiments, HSC mobilizing activity is measured using at least the CD34⁺ marker phenotype.

TABLE 1 CD34⁺ CD34⁺ CD38⁻ CD34⁺ Lin⁻ Thy1⁺ CD34⁺ c-kit⁺ CD34⁺ Tie⁺ CD34⁺ CD133⁺ CD34⁻ Lin⁻ CD133⁻ CD7⁻ CD34⁺ CD38⁻ Lin⁻ Rhodamine123^(low) CD34⁺ CD38⁻ Lin⁻ CD45RA⁻ Rhodamine123^(low) CD49f⁺

5.2.4. Administration of CXCL12-Interacting Heparinoid

In one aspect, the methods described herein comprise administering to a subject receiving an antineoplastic treatment regimen a CXCL12-interacting heparinoid, wherein the cancer is one that is privileged by CXCL12-CXCR4 interaction against therapeutic intervention. In certain embodiments, the cancer is one in which neoplastic cells, such as cancer stem cells, migrate to and/or reside in privileged anatomic sites. In some embodiments, the cancer is characterized by stromal expression of CXCL12. In embodiments, the CXCL12-interacting heparinoid is administered in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen.

In another aspect, the methods comprise administering to a subject receiving a treatment regimen for a hematopoietic stem cell disorder a heparin derivative capable of inhibiting binding of CXCL12 to CXCR4. The heparin derivative is administered in an amount and at a time effective to enhance effectiveness of the treatment regimen.

5.2.4.1. Routes of Administration

The CXCL12-interacting heparinoid can be administered in the methods described herein by any one or more of a variety of routes.

In certain embodiments, the CXCL12-interacting heparinoid is administered intravenously. In certain embodiments, the CXCL12-interacting heparinoid is administered by bolus intravenous administration. In some embodiments, a bolus dose is administered over less than a minute, about a minute, about 2 minutes, about 3 minutes, about 4 minutes, or about 5 minutes. In some embodiments, the CXCL12-interacting heparinoid is administered by continuous intravenous infusion. In other embodiments, the CXCL12-interacting heparinoid is administered by subcutaneous injection. In some embodiments, the CXCL12-interacting heparinoid is administered as one or more bolus intravenous injections preceded and/or followed by continuous infusion.

5.2.4.2. Effective Amounts

The CXCL12-interacting heparinoid is administered in an amount effective to enhance efficacy of the treatment regimen. In methods of treating cancers, the CXCL12-interacting heparinoid is administered in an amount effective to enhance the efficacy of the antineoplastic treatment regimen. In methods of treating hematopoietic stem cell disorders, the CXCL12-interacting heparinoid is administered in an amount effective to enhance the efficacy of the treatment regimen used to treat the disordered HSC cells.

In some embodiments, the enhancement of treatment efficacy is with respect to one or more of the anti-tumor effect, the response rate (e.g., overall or objective response rate), the time to disease progression or the survival rate (e.g., progression free survival or overall survival). Anti-tumor effects include, but are not limited to, inhibition of tumor growth, tumor growth delay, regression of tumor, shrinkage of tumor, increased time to regrowth of tumor on cessation of treatment, and/or slowing of disease progression.

In typical embodiments, the CXCL12-interacting heparinoid is administered in an amount effective to mobilize neoplastic cells from a privileged anatomic site. Typically, the amount is effective to mobilize neoplastic cells from the bone marrow.

In some embodiments, the CXCL12-interacting heparinoid is administered in an amount effective to increase the number of cancer cells outside the bone marrow, e.g., in the peripheral blood and/or peripheral tissues. In some embodiments, the CXCL12-interacting heparinoid is administered in an amount effective to decrease the number of cancer cells in the bone marrow.

In preferred embodiments, the CXCL12-interacting heparinoid is administered in an amount effective to decrease the number of cancer cells in the bone marrow by at least 50%. In certain embodiments, the CXCL12-interacting heparinoid is administered in an amount effective to decrease the number of cancer cells in the bone marrow by at least 60%, at least 70%, at least 80%, or more. In specific embodiments, the CXCL12-interacting heparinoid is administered in an amount effective to decrease the number of cancer cells in the bone marrow by at least 85%, at least 90%, even by as much as 95% or more.

In certain embodiments, the diminution of cancer cells in the bone marrow is measured by visual inspection of bone marrow biopsies.

In some embodiments, the mobilization of bone-marrow residing cancer cells to the peripheral blood or tissues, and/or the decrease in the number of cancer cells in the bone marrow, is determined by detecting and quantifying a cancer cell marker or a set of cell markers distinctive for or indicative of the cancer cell.

In some embodiments, the cancer cell marker can include one or more of a cell surface marker, a cellular enzyme, a cellular genotype, and combinations thereof. By way of example and not limitation, markers useful for assessing mobilization of the relevant cancer cells are given below.

TABLE 2 Cancer Type Markers Lung cancer Adrenocorticotropic Hormone (ACTH) Calcitonin EGFR mutation Breast cancer Cancer Antigen 15-3 Cancer Antigen 549 C-erb B-2 Prostate Cancer Acid Phosphatase Prostate Specific Antigen Carcinoembryonic antigen Kidney Cancer PAX-2 Renal cell carcinoma marker antigen (RCCM) Kidney-specific cadherin (KSC) Neuroblastoma Cyclin D1 GALNT13 GD2 disialoganglioside Acute Lymphoblastic Leukemia Neprilysin (CALLA antigen) TEL-AML1 fusion Acute Myeloid Leukemia NPM1 mutations FLT3 mutations CMBPA mutations Chronic Lymphocytic leukemia CD38 zeta-associated protein (ZAP)-70 IgVH mutations Chronic Myelogenous Leukemia Philadelphia Chromosome (Ph1:bcr-abl fusion) Acute Monocytic Leukemia CD13 CD33 CD11b, CD11c

Methods for detecting the cell markers and cancer cells include, among others, flow cytometry (e.g., fluorescence activated cell sorting); immune detection (e.g., histochemistry); polymerase chain reaction (and other methods for detecting gene polymorphisms); fluorescence in situ hybridization; gene expression profiling; proteomics; morphological analysis; and combinations thereof. The sensitivity of each of the detection techniques can vary, and the appropriate method selected based on sensitivity appropriate for the treatment. For example, for acute myeloid leukemia (AML), detection sensitivity—the number of blast cells that can be detected per 100,000 cells—of standard detection approaches is as follows: morphological detection with immunohistochemistry can detect from about 1000 to about 5000 blast cells per 100,000 cells; karyotype analysis can detect about 5000 blast cells per 100,000 cells; flow cytometry can detect about 10 blast cells per 100,000 cells; and polymerase chain reaction can detect about 0.1 blasts per 100,000 cells. In some embodiments, the bone is imaged, for example with a MRI scan, a CT scan, and/or a PET scan to detect presence of cancer in the bone marrow, metastasis of cancers into the bone marrow, and/or any changes arising from administration of the CXCL12-interacting heparinoid.

In some embodiments, the CXCL12-interacting heparinoid is administered as an intravenous bolus. In certain embodiments, the CXCL12-interacting heparinoid is administered in an intravenous bolus of no more than about 1 mg/kg patient body weight. In typical intravenous bolus dosing embodiments, the CXCL12-interating heparinoid is administered at a dose of no more than about 25 mg/kg. In various embodiments, the CXCL12-interacting heparinoid is administered at an intravenous bolus dose of at least about 2 mg/kg, at least about 3 mg/kg, at least about 4 mg/kg, at least about 5 mg/kg, at least about 6 mg/kg, at least about 7 mg/kg, at least about 8 mg/kg, at least about 9 mg/kg, even at least about 10 mg/kg. In some embodiments, the bolus is at least about 15 mg/kg, even at least about 20 mg/kg. In certain preferred embodiments, the bolus is about 4 mg/kg. In certain other preferred embodiments, the bolus is about 8 mg/kg. In certain preferred embodiments, the bolus is about 20 mg/kg.

In some embodiments, the CXCL12-interacting heparinoid is administered in a bolus of from about 2 to about 25 mg/kg, from about 2 mg/kg to about 20 mg/kg, from about 2 mg/kg to about 15 mg/kg, from about 3 mg/kg to about 10 mg/kg, or from about 4 mg/kg to about 8 mg/kg.

In some embodiments, the CXCL12-interacting heparinoid is administered as an intravenous infusion. In certain embodiments, the infusion is at a dose rate of at least about 0.1 mg/kg/hr, at least about 0.2 mg/kg/hr, at least about 0.3 mg/kg/hr, at least about 0.4 mg/kg/hr, at least about 0.5 mg/kg/hr, at least about 1 mg/kg/hr, even at least about 2 mg/kg/hr. In various embodiments, the CXCL12-interacting heparinoid is administered at an infusion rate of no more than about 5 mg/kg/hr. In certain embodiments, the CXCL12-interacting heparinoid is administered at an infusion rate of no more than about 4 mg/kg/hr, 3 mg/kg/hr, about 2 mg/kg/hr, even no more than about 1 mg/kg/hr.

In typical embodiments, infusions at the above-described dose rates are administered continuously for up to 7 days. In certain embodiments infusions at the above-described dose rates are administered continuously for up to 6 days, 5 days, 4 days, or 3 days. In some embodiments, infusions at the above-described dose rates are administered continuously for up to 2 days or up to 24 hours. In some embodiments, infusions at the above-described rates are administered for up to 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 12 hours, 16 hours, or up to 24 hours or more. In certain embodiments, the infusions at the above described dose rates are administered for the duration of each cycle of treatment.

In some embodiments, the CXCL12-interacting heparinoid is administered as an initial bolus of about 20 mg/kg, optionally followed by an infusion of up to about 2 mg/kg/hour for up to about 4 hours, 8 hours, 12 hrs, 16 hours, even up to about 24 hours. In one embodiment, the CXCL12-interacting heparinoid is administered as an initial bolus of about 8 mg/kg, optionally followed by an infusion of about 0.5 mg/kg/hour for at least about 8 hours. In some embodiments, the CXCL12-interacting heparinoid is administered as an intravenous bolus at a dose of about 4 mg/kg, optionally followed by an intravenous infusion of the CXCL12-interacting heparinoid at a dose of about 0.25 mg/kg/hr—about 0.375 mg/kg/hr for at least 24 hours. In some embodiments, the CXCL12-interacting heparinoid is administered as an intravenous bolus at a dose of about 4 mg/kg, followed by a continuous intravenous infusion at a rate of 0.25 mg/kg/hr for a total of 7 days. In some embodiments, the CXCL12-interacting heparinoid is administered as a 4 mg/kg bolus on Day 1 followed by a continuous intravenous infusion of 0.25 mg/kg/hr for days 1 through 5 of each 28-day cycle.

For subcutaneous administration, CXCL12-interacting heparinoid can be administered at doses ranging from about 25 mg to about 400 mg, about 50 mg to about 300 mg, or about 75 mg to about 200 mg, in volumes of 2.0 mL or less per injection. In some embodiments, the CXCL12-interacting heparinoid at the above-described dosages are administered subcutaneously each day for up to 7 days. In certain embodiments, the CXCL12-interacting heparinoid at the above-described dosages are administered subcutaneously each day for up to 6 days, 5 days, 4 days, or 3 days. In some embodiments, CXCL12-interacting heparinoid at the above-described dosages are administered subcutaneously for up to 2 days or up to 24 hours. In some embodiments, CXCL12-interacting heparinoid at the above-described dosages are administered subcutaneously each day for the duration of the cycle of treatment.

5.2.4.3. Effective Timings

In various embodiments, the CXCL12-interacting heparinoid is administered adjunctively with the antineoplastic treatment regimen. The terms “adjunctive administration”, “adjunctively administering” or “administering adjunctive to” are used interchangeably herein to mean administering the CXCL12-interacting heparinoid in therapeutically effective temporal proximity to the antineoplastic treatment regimen, that is, in sufficient temporal proximity to administration of the antineoplastic treatment regimen as to enhance the efficacy of the antineoplastic treatment regimen. In some embodiments, the CXCL12-interacting heparinoid is administered prior to treatment with the antineoplastic treatment. In some embodiments, the CXCL12-interacting heparinoid is administered concurrently with treatment with the antineoplastic treatment regimen. In some embodiments, the CXCL12-interacting heparinoid is administered prior to and concurrently with the antineoplastic treatment regimen.

In the methods described herein, the antineoplastic treatment regimen can involve one or more of an induction therapy, one or more of a consolidation therapy, and/or one or more of a maintenance therapy. In some embodiments, the consolidation or maintenance therapy can be optional. For example, a treatment regimen can include an induction therapy followed by maintenance therapy, or an induction therapy followed by consolidation therapy without any maintenance therapy. It is also to be understood that each of induction therapy, consolidation therapy, and maintenance therapy can have one or more cycles of treatment. As such, in some embodiments, the induction therapy can have one or more cycles of induction treatment; the consolidation therapy can have one or more cycles of consolidation treatment; and the maintenance therapy can have one or more cycles of maintenance treatment.

Thus, in various embodiments, the CXCL12-interacting heparinoid is administered adjunctively to one or more cycles of induction therapy. In certain embodiments, the CXCL12-interacting heparinoid is administered adjunctively to one or more cycles of consolidation therapy. In some embodiments, the CXCL12-interacting heparinoid is administered adjunctively to one or more cycles of maintenance therapy.

In some embodiments, the CXCL12-interacting heparinoid is administered at a time sufficiently prior to treatment with the antineoplastic treatment regimen as to mobilize the cancer cells from the privileged anatomic site, such as the bone marrow, before administration of the antineoplastic agent(s). In some embodiments, the CXCL12-interacting heparinoid is administered at least about 1 hr to about 24 hr prior to treatment with the antineoplastic therapeutic agent. In some embodiments, the CXCL12-interacting heparinoid is administered at least 2 days or more, or 3 days or more prior to treatment with the antineoplastic therapeutic. In certain embodiments, the CXCL12-interacting heparinoid is administered both prior to and concurrently with the antineoplastic treatment regimen.

In some embodiments, the CXCL12-interacting heparinoid is administered prior to induction therapy, particularly prior to each cycle of induction therapy with an antineoplastic therapeutic. In some embodiments, the CXCL12-interacting heparinoid is administered at a high dose prior to the induction therapy, particularly prior to each cycle of induction therapy. In some embodiments, the CXCL12-interacting heparinoid is administered prior to, during and optionally, following, treatment with the antineoplastic therapeutic used in the induction therapy, such as by continuous administration, for example to keep cancer cells from reestablishing residence in the bone marrow or other privileged anatomic site.

In some embodiments, the CXCL12-interacting heparinoid is administered prior to consolidation therapy, particularly prior to each cycle of consolidation therapy with an antineoplastic therapeutic agent. In some embodiments, the CXCL12-interacting heparinoid is administered at a high to moderate dose prior to the consolidation therapy, particularly prior to each cycle of consolidation therapy. In some embodiments, the CXCL12-interacting heparinoid is administered prior to, during and optionally, following, treatment with the antineoplastic therapeutic used in the consolidation therapy, such as by continuous administration, for example to keep cancer cells from reestablishing residence in the bone marrow or other privileged anatomic sites.

In some embodiments, the CXCL12-interacting heparinoid is administered prior to maintenance therapy, particularly prior to each cycle of maintenance therapy. In some embodiments, the CXCL12-interacting heparinoid is administered at a high to moderate dose, particularly at a moderate dose, prior to maintenance therapy, particularly prior to each cycle of maintenance therapy. In some embodiments, the CXCL12-interacting heparinoid is administered prior to, during, and optionally following treatment with the antineoplastic therapeutic in the maintenance therapy used in the maintenance therapy, such as by continuous administration, for example to keep cancer cells from reestablishing residence in the bone marrow or other privileged anatomic sites.

In some embodiments, the CXCL12-interacting heparinoid is administered as an adjunct to induction therapy, and is administered at high dose. In some embodiments, the CXCL12-interacting heparinoid is administered as an adjunct to consolidation therapy, and is administered in a high dose to a moderate dose. In some embodiments, the CXCL12-interacting heparinoid is administered as an adjunct to maintenance therapy, particularly at a high to a moderate dose, more particularly a moderate dose of the CXCL12-interacting heparinoid.

In some embodiments, the subject is treated with a high dose of the CXCL12-interacting heparinoid prior to induction therapy with the antineoplastic therapeutic, followed by treatment with a high to moderate dose of the CXCL12-interacting heparinoid for each cycle of a consolidation and/or maintenance therapy with the antineoplastic therapeutic. In some embodiments, the subject is treated with a high dose of the CXCL12-interacting heparinoid prior to induction therapy with the antineoplastic therapeutic, followed by treatment with a high to moderate dose of the CXCL12-interacting heparinoid for each cycle of a consolidation therapy, and treatment with a high to moderate dose, particularly a moderate dose of the CXCL12-interacting heparinoid for each cycle of a maintenance therapy. In each cycle of treatment, the CXCL12-interacting heparinoid can be administered as a bolus prior to administration of the antineoplastic therapeutic. In some embodiments, the bolus administration can be followed by a continuous administration, particularly during and/or subsequent to treatment with the antineoplastic therapeutic.

As discussed above, in some embodiments, the CXCL12-interacting heparinoid is administered in coordination with the cycles of treatment with an antineoplastic therapeutic, particularly a non-myelosuppressive antineoplastic therapeutic.

In some embodiments the CXCL12-interacting heparinoid is administered in coordination with hypomethylation agents. In certain embodiments the hypomethylation agent is azacitidine. In certain embodiments, the azacitidine is administered at 75 mg/m² as a 15 minute intravenous infusion daily on days 1 through 5 of each 28-day cycle and a heparinoid is administered as a 4 mg/kg bolus on Day 1 followed by a continuous intravenous infusion of 0.25 mg/kg/hr for days 1 through 5 of each 28-day cycle.

An exemplary treatment protocol follows the following schedule: treatment cycle length: every 21 days for 4 cycles. On days 1 to 3 of each cycle, the subject is treated with an antineoplastic therapeutic, such as a non-myelosuppressive therapeutic. ODSH is administered as an 8 hour infusion, on days 1-5, of weeks 1, 2 and 3 and then on days 1-3 of subsequent cycles as an 8 hour infusion. The dose is about 8 mg/kg bolus followed by about 0.5 mg/kg/hour infusion. In some embodiments, the dose is about 20 mg/kg bolus followed by about 2 mg/kg/hour infusion, such as during the induction therapy.

5.2.4.4. Duration and Frequency of Administration

In typical embodiments, the CXCL12-interacting heparinoid is administered for up to 1 hour. In various embodiments, the CXCL12-interacting heparinoid is administered for up to 4 hours. In certain embodiments, the CXCL12-interacting heparinoid is administered for up to 6 hours, even up to 8 hours. In some embodiments, the CXCL12-interacting heparinoid is administered for up to 12 hours, 18 hours, even up to 24 hours. In certain embodiments, the CXCL12-interacting heparinoid is administered for up to 2 days, 3 days, 4 days, 5 days, 6 days, or a week or more. The CXCL12-interacting heparinoid can be administered, in some embodiments, for periods of more than a week, including 1 month, 2 months, 3 months or more.

Typically, CXCL12-interacting heparinoid administration is repeated. For example, in certain embodiments, heparinoid is administered once daily, twice daily, three times daily, four times daily, five times daily, every two days, every three days, every five days, once a week, once every two weeks, once a month, every other month, semi-annually, or annually. In some embodiments, the CXCL12-interacting heparinoid is administered at regular intervals over a period of several weeks, followed by a period of rest, during which no heparinoid is administered. For example, in some embodiments, CXCL12-interacting heparinoid is administered for one, two, three, or more weeks, followed by one, two, three, or more weeks without heparinoid administration. The repeated administration can be at the same dose or at a different dose. The CXCL12-interacting heparinoid can be administered in one or more bolus injections, one or more infusions, or one or more bolus injections followed or preceded by infusion.

The frequency of dosing can be based on and adjusted for the pharmacokinetic parameters of the CXCL12-interacting heparinoid and the route of administration. Dosages are adjusted to provide sufficient levels of the CXCL12-interacting heparinoid or to maintain the desired physiological effect, particularly a therapeutic effect. Any effective administration regimen regulating the timing and sequence of doses may be used, as discussed herein.

Accordingly, the pharmaceutical compositions can be administered in a single dose, multiple discrete doses, continuous infusion, sustained release depots, or combinations thereof, as required to maintain desired minimum level of the agent. Daily dosages may vary, depending on the specific activity of the particular heparinoid. Depending on the route of administration, a suitable dose may be calculated according to, among others, body weight, body surface area, or organ size. The final dosage regimen will be determined by the attending physician in view of good medical practice, considering various factors that modify the action of drugs, e.g., the agent's specific activity, the severity of the disease state, the responsiveness of the patient, the age, condition, body weight, sex, and the like. Additional factors that may be taken into account include time and frequency of administration, drug combination(s), reaction sensitivities, and tolerance/response to therapy. Further refinement of the dosage appropriate for treatment involving any of the formulations mentioned herein is done by the skilled practitioner, especially in light of the dosage information and assays disclosed, as well as the pharmacokinetic data observed in clinical trials. The amount and/or frequency of the dosage can be altered, increased, or reduced, depending on the subject's response and in accordance with standard clinical practice. The proper dosage and treatment regimen can be established by monitoring the progress of therapy using conventional techniques known to skilled artisans. Appropriate dosages may be ascertained through use of established assays for determining concentration of the CXCL12-interacting heparinoid in a body fluid or other sample together with dose response data.

In embodiments in which CXCL12-interacting heparinoid is administered to a subject in combination with other therapeutic agents, the CXCL12-interacting heparinoid is administered in a therapeutically effective temporal proximity to the treatment regimen with the other therapeutic. Administration of a CXCL12-interacting heparinoid can be concurrent with (at the same time), sequential to (at a different time but on the same day, e.g., during the same patient visit), or separate from (on a different day) the treatment with the other therapeutic. In some embodiments, the CXCL12-interacting heparinoid is administered concurrently, sequentially, and/or separately from the other agent or therapy being administered. When administered sequentially or separately, the CXCL12-interacting heparinoid can be administered before, after, or both before and after the other treatment.

In embodiments in which the CXCL12-interacting heparinoid is administered in combination with treatment with another therapeutic agent, the CXCL12-interacting heparinoid can be administrated via the same or different route as the other therapeutic administered in temporal proximity. In some embodiments, the CXCL12-interacting heparinoid is administered concurrently or sequentially by the same route. For example, in some embodiments, the CXCL12-interacting heparinoid and the other therapeutic are administered intravenously, either concurrently or sequentially. Optionally, as part of a treatment regimen, the CXCL12-interacting heparinoid can further be administered separately (on a different day) from the other therapeutic by a different route, e.g., subcutaneously. In some embodiments, the CXCL12-interacting heparinoid is administered intravenously on the same day, either at the same time (concurrently), a different time (sequentially), or both concurrently and sequentially with the other therapeutic, and is also administered subcutaneously on one or more days when the patient is not receiving other treatment. In some embodiments, the CXCL12-interacting heparinoid is administered concurrently or sequentially by a different route. Optionally, as part of a treatment regimen, the CXCL12-interacting heparinoid can further be administered separately (on a different day) from the other therapeutic by the same or different route as that by which the other therapeutic is administered.

Other methods for delivering CXCL12-interacting heparinoids in the methods presented herein can be adapted from those are described in U.S. Pat. No. 4,654,327, which describes oral administration of heparin in the form of a complex with a quaternary ammonium ion; U.S. Pat. No. 4,656,161, which describes a method for increasing the enteral absorbability of heparinoids by orally administering the drug along with a non-ionic surfactant such as polyoxyethylene-20 cetyl ether, polyoxyethylene-20 stearate, other polyoxyethylene (polyethylene glycol)-based surfactants, polyoxypropylene-1 5 stearyl ether, sucrose palmitate stearate, or octyl-beta-D-glucopyranoside; U.S. Pat. No. 4,703,042, which describes oral administration of a salt of polyanionic heparinic acid and a polycationic species; and U.S. Pat. No. 5,714,477, which describes a method for improving the bioavailability of heparinoids by administering in combination with one or several glycerol esters of fatty acids.

5.2.5. Optional Steps

In some embodiments, the method of treatment further comprises the step of measuring or determining the number of cancer cells mobilized by treatment with the CXCL12-interacting heparinoid, particularly prior to treatment with the antineoplastic therapeutic. For example, a measurement of the number of cancer cells can be taken prior to administration of the CXCL12-interacting heparinoid and subsequent to administration of the CXCL12-interacting heparinoid to determine the increase in the number of cancer cell mobilized by the CXCL12-interacting heparinoid treatment. However, it is to be understood that, in some embodiments, the treatments herein can be given before metastasis or even when no increase in peripheral cancer cells are measured, particularly given that in some cancers a reservoir of cancer cells can remain in the bone marrow at levels not readily detectable, for example where there is minimal residual disease. Moreover, mobilization per se need not be a requisite condition for treatment because the CXCL12-interacting heparinoid may dislodge the cancer cells sufficiently to increase susceptibility to the antineoplastic therapeutic without inducing movement of cancer cells to the peripheral blood or tissues.

5.3. Pharmaceutical Compositions and Unit Dosage Forms of CXCL12-Interacting Heparinoids

In the methods presented herein, the CXCL12-interacting heparinoid is administered in the form of a pharmaceutical composition.

In typical embodiments, the pharmaceutical composition comprises the CXCL12-interacting heparinoid and a pharmaceutically acceptable carrier, excipient, and/or diluent, and is formulated for parenteral administration.

5.3.1. Pharmaceutical Compositions Formulated for i.v. Administration

In certain embodiments, pharmaceutical compositions of the CXCL12-interacting heparinoid are formulated in volumes and concentrations suitable for intravenous administration. In some embodiments, the composition is formulated for bolus administration. In certain embodiments, pharmaceutical compositions of the CXCL12-interacting heparinoid are formulated in volumes and concentrations suitable for intravenous infusion.

Typical embodiments formulated for intravenous administration comprise the CXCL12-interacting heparinoid in concentrations of at least about 10 mg/ml. In various embodiments, the CXCL12-interacting heparinoid is present in a concentration of at least about 15 mg/ml, at least about 20 mg/ml, at least about 30 mg/ml, at least about 40 mg/ml, at least about 50 mg/ml. In certain embodiments, the CXCL12-interacting heparinoid is packaged in sterile-filled 10 ml glass vials containing an isotonic 50 mg/ml solution of heparinoid in buffered saline.

5.3.2. Pharmaceutical Compositions Formulated for s.c. Administration

In various embodiments, the pharmaceutical composition is formulated for subcutaneous administration.

In certain such embodiments, the CXCL12-interacting heparinoid is associated with multivalent cations. The term “associated”, when used to describe the relationship between a heparinoid and a cation, means a chemically relevant association. The association may be as a salt, ion/counterion, complex, binding, coordination or any other chemically relevant association. The exact nature of the association will be readily apparent to a person of skill in the art depending on the form of the composition.

In various such embodiments, the multivalent cations are selected from cations having a charge of +2, +3, +4, or greater. In some embodiments, the multivalent cation is an ion that contains both positive and negative charges, with a net charge greater than +1. Exemplary multivalent cations include metal ions, amino acids, and other organic and inorganic cations. In certain embodiments, the ion is a metal ion that is Zn²⁺, Ca²⁺, Mg²⁺ or Fe²⁺. In a specific embodiment, the cation is Ca²⁺. In another specific embodiment, the cation is Mg²⁺.

In certain of the embodiments of pharmaceutical composition intended for subcutaneous administration, the CXCL12-interacting heparinoid is associated primarily with one species of multivalent cation. In other embodiments, the CXCL12-interacting heparinoid is associated with several different multivalent cation species. In specific embodiments, the CXCL12-interacting heparinoid is associated with Mg′ and Ca′.

In the multivalent cation embodiments, multivalent cations may be introduced to the CXCL12-interacting heparinoid composition at any step.

In one embodiment, the CXCL12-interacting heparinoid is substantially desulfated at the 2-O and 3-O positions, and the multivalent cation is present during alkaline hydrolysis of the heparin starting material. In certain embodiments, the multivalent cation is present as the chloride salt. In certain embodiments, the multivalent cation is present as the hydroxide salt. In one embodiment, the chloride salt is preferred for use during solution phase alkaline hydrolysis. In another embodiment, the hydroxide salt is preferred for use during solid phase alkaline hydrolysis. In another embodiment, the hydroxide salt is preferred for use when alkaline hydrolysis is performed as a paste. Certain multivalent cations may affect the level of desulfation if present during alkaline hydrolysis, and may be used to achieve desired levels of desulfation. The amount of the multivalent cation may be titrated to control the amount of desulfation as described in U.S. Pat. No. 5,296,471 at Example 4 therein.

Thus, when a multivalent cation is used during alkaline hydrolysis, the multivalent cation concentration used should be adjusted based on both the desired level of desulfation and the desired concentration of the final product. The molar multivalent cation concentration used during alkaline hydrolysis may be substantially less than the molar heparin concentration. Preferably, the molar ratio (multivalent cation:heparin) is about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, or 1.5, or any ranges composed of those values. Preferably, the concentration of the multivalent cation used during alkaline hydrolysis is about 0.01 mM, 0.05 mM, 0.1 mM, 0.5 mM, 1 mM, 5 mM, 10 mM, 20 mM, 50 mM, 100 mM, 250 mM, 500 mM or 1M or any range composed of those numbers.

In certain embodiments, primarily monovalent cations are present during the cold alkaline hydrolysis step, and the multivalent cation is added later, during reconstitution of the lyophilate. In a most preferred embodiment, either MgCl₂ or CaCl₂ is added at high concentration during reconstitution of the lyophilate.

The multivalent cation concentration used during reconstitution may be equal to the concentration of the cation used during alkaline hydrolysis. Preferably, the multivalent cation concentration is at least about 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 15-fold, 20-fold, 25-fold, 30-fold, 50-fold, 75-fold, 100-fold, 150-fold, 200-fold, 250-fold, 500-fold, or 1000-fold the concentration of the cation used during alkaline hydrolysis. Preferably, the concentration of the multivalent cation used during reconstitution is about 0.1 M, 0.5 M, 1 M, 2 M, 3 M, 4 M, 5M, or greater. Most preferably, the concentration is about 2 M.

Excess cations can be removed by any method known to those in the art. One preferred method of removing excess cations is the use of a desalting column. Another preferred method of removing excess cations is dialysis. After removal of excess ions, the solution preferably has about equal, 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 15-fold, 20-fold, 25-fold, 30-fold, 50-fold, 75-fold, 100-fold, 150-fold, 200-fold, 250-fold, 500-fold, or 1000-fold greater multivalent cation concentration to monovalent cation concentration. The solution may also be free or substantially free of monovalent cations.

In typical embodiments, the final concentration of CXCL12-interacting heparinoid in the pharmaceutical composition is between 0.1 mg/mL and 600 mg/mL. In certain embodiments, the final concentration of partially desulfated heparin in the pharmaceutical composition is between 200 mg/mL and 400 mg/mL.

In some embodiments, the concentration of heparinoid is greater than about 25 mg/mL. In certain embodiments, the concentration of heparinoid is greater than about 50 mg/mL. In a variety of embodiments, the concentration of heparinoid is greater than about 60 mg/mL, 70 mg/mL, 80 mg/mL, 90 mg/mL, or 100 mg/mL.

In specific embodiments, the CXCL12-interacting heparinoid is present in the pharmaceutical composition in a concentration greater than about 110 mg/mL, 120 mg/mL, 130 mg/mL, 140 mg/mL, 150 mg/mL, 160 mg/mL, 170 mg/mL, 180 mg/mL, or even greater than about 190 mg/mL or 200 mg/mL. In specific embodiments, the CXCL12-interacting heparinoid is present in the pharmaceutical composition at a concentration of about 175 mg/mL. In another embodiment, the CXCL12-interacting heparinoid is present in the pharmaceutical composition at a concentration of about 200 mg/mL. In one embodiment, the CXCL12-interacting heparinoid is present in the pharmaceutical composition at a concentration of 400 mg/mL.

In certain embodiments, the concentration of CXCL12-interacting heparinoid is 50 mg/mL to 500 mg/mL, 100 mg/mL to 400 mg/mL, or 150 mg/mL to 300 mg/mL. In specific embodiments, the concentration is 50 mg/mL, 100 mg/mL, 150 mg/mL, 200 mg/mL, 250 mg/mL, 300 mg/mL, 350 mg/mL, 400 mg/mL, 450 mg/mL or 500 mg/mL. In certain currently preferred embodiments, the concentration is 200 mg/mL, 300 mg/mL or 400 mg/mL.

In typical embodiments, the pharmaceutical composition has a viscosity of less than about 100 cP. In various embodiments, the pharmaceutical composition has a viscosity of less than about 80 cP. In certain embodiments, the pharmaceutical composition has a viscosity of less than about 60 cP. In particular embodiments, the pharmaceutical composition has a viscosity of less than about 20 cP.

In typical embodiments, the pharmaceutical composition has an osmolality less than about 2500 mOsm/kg. In various embodiments, the pharmaceutical composition has an osmolality between about 150 mOsm/kg and about 500 mOsm/kg. In certain embodiments, the pharmaceutical composition has an osmolality between about 275 mOsm/kg and about 300 mOsm/kg. In a particular embodiment, the pharmaceutical composition has an osmolality of about 285 mOsm/kg. In a specific embodiment, the pharmaceutical composition is isotonic.

6. EXAMPLES

Practice of the various embodiments of the treatment methods can be understood through reference to the following examples, which are provided by way of illustration and are not intended to be limiting.

6.1. Example 1: CX-01 ODSH Attenuates Myelosuppressive Side Effects of Induction Chemotherapy in Treatment of Acute Myeloid Leukemia, and Surprisingly Improves Remission Rate

A single arm open-label clinical study was conducted at multiple trial sites (University of Utah, Georgia Regents University, and Medical University of South Carolina) in patients with newly diagnosed acute myeloid leukemia (AML) to confirm that ODSH could accelerate platelet and white blood cell (WBC) recovery in patients receiving induction chemotherapy with a regimen known to have myelosuppressive side effects.

All patients received the following standard (“7+3”) induction regimen,

-   -   Idarubicin (12 mg/m²/day) by short intravenous infusion on Days         1, 2, and 3; and     -   Cytarabine (100 mg/m²) as a continuous intravenous infusion over         24 hours (Days 1 through 7).

All patients also received CX-01, a substantially 2-O, 3-O-desulfated heparin derivative (ODSH) as an intravenous bolus immediately after the idarubicin dose on Day 1, at a dose of 4 mg/kg, followed by a continuous intravenous infusion at a dose of 0.25 mg/kg/hr for a total of 7 days (Days 1 through 7).

ODSH was manufactured under cGMP conditions by Scientific Protein Labs (Waunakee, Wis.) by cold alkaline hydrolysis of USP porcine intestinal unfractionated heparin during lyophilization. This process removes 2-O and 3-O sulfates, leaving N-sulfates and 6-O sulfates and carboxylates largely intact (Fryer et al., J. Pharmacol. Exp. Ther. 282:208-2219 (1997)). Seven serial 1.2 kg batches of material have shown an average molecular weight of 11.7±0.3 kDa, low affinity for anti-thrombin III (Kd=339 μm, or 4 mg/ml) (vs. 1.56 μm or 22 μg/ml for UFH), and consistently reduced USP anticoagulant activity (7±0.3 U of anticoagulant activity/mg), anti-Xa activity (1.9±0.1 U/mg), and anti-IIa activity (1.2±0.1 U/mg) as compared with those of heparin (165-190 U/mg activity for all 3 assays). Drug product was formulated by Pyramid Laboratories (Costa Mesa, Calif.) in sterile-filled 10 ml glass vials containing an isotonic 50 mg/ml solution of sodium ODSH in buffered saline.

Twelve patients were enrolled. The median age was 56 (range 22-74). Based on cytogenetic, molecular, or antecedent hematologic disorder, 9 of 12 patients fell into the intermediate or poor risk categories. Patients did not receive growth factor support, that is, Neupogen or similar agents, during induction cycles. Complete remission at the end of the induction cycle was assessed using International Working Group (IWG) criteria (see, e.g., Cheson et al., J. Clin. Oncol. 21:4642 (2003)).

Platelet, neutrophil, and WBC recovery of the ODSH-treated AML patients was compared with the recovery in historical control patients receiving identical doses of idarubicin and cytarabine as induction therapy in a previous clinical study comparing idarubicin and daunorubicin in combination with cytarabine (Vogler et al., J. Clin. Oncol. 10(7):1103-11(1992)). In the previous study, 101 patients received idarubicin 12 mg/m² on days 1, 2, and 3 and cytarabine 100 mg/m² on days 1-7. Growth factors were not administered to any patient.

Table 3 compares hematologic recovery parameters as reported in the prior study to those observed in the current study in which patients additionally received ODSH, as described above.

TABLE 3 Idarubicin + Idarubicin + Cytarabine Cytarabine + (n = 101) ODSH (n = 12) Time to platelet count > 50,000 35 days 22 days Time to WBC > 1000 31 days 21 days

In the current study, 11 out of 12 patients (92%), including two patients who received an incomplete course of chemotherapy (3 and 5 days, respectively), had a morphologic complete remission by IWG criteria at the end of a single induction cycle. The only patient who did not obtain a complete morphologic remission at the end of induction therapy presented with extensive mediastinal and peripheral lymphadenopathy involved with granulocytic sarcomas, accompanying bone marrow involvement with AML. This patient had residual extramedullary disease at the end of his induction cycle, and achieved a complete remission with a subsequent cycle of FLAG-Ida chemotherapy without ODSH.

With 9 of 12 patients having intermediate or poor risk disease prior to treatment, and with two of these patients having received an incomplete course of treatment, the 92% complete remission rate after the first induction cycle is higher than would otherwise be expected based on historical data, as shown in Table 4.

TABLE 4 Idarubicin + Idarubicin + Cytarabine Cytarabine + (n = 101) ODSH (n = 12) Complete response with 58% 92% first induction cycle Furthermore, 10 of the 12 patients remain in complete remission 5-13 months after having been enrolled in the study.

FIG. 3 compares complete response rate of the 11 patients who entered the clinical trial with primary AML to historical controls, indicated by asterisk. The historical controls are 1,980 patients registered to 6 studies conducted by the Eastern Cooperative Oncology Group (data from Rowe et al., Cancer 116(21):5012-5021 (2010).

Post-Induction Treatment and Outcomes

Of the 12 patients enrolled, 4 were not eligible to receive post-induction treatment on study due to either age ≥60 years, induction failure, or incomplete induction. Of the other patients, one developed a line-associated deep venous thrombosis requiring systemic anticoagulation and was taken off study before consolidation. The remaining 4 patients each received one or more cycles of HIDAC and CX-01 consolidation treatment on study as follows: Patient 1005 completed all four cycles on study; Patient 1009 received 3 cycles of consolidation on study and asked to be taken off study before receiving the fourth cycle of HIDAC consolidation; Patient 3001 completed 1 consolidation cycle, withdrew from study and was lost to follow-up; and Patient 3003 received 2 cycles of consolidation on study before relapsing. Four patients who completed induction received an allogeneic stem cell transplant in CR1 (Patients 1002, 1006, 1010, and 3002). Six patients relapsed at a median time of 8 months. Among those were Patient 2001 who had not completed induction and relapsed 7 weeks after diagnosis and Patient 3001 who received only 1 cycle of consolidation therapy, and relapsed 13.5 months after diagnosis.

With a median follow-up of 14.2 months, median event free survival is 13.5 months and median OS is 13.6+ months.

6.2. Example 2: CX-01 ODSH Mobilizes Cells of Multiple Lineages from Bone Marrow

Bone marrow biopsies were obtained in the AML, trial described in Example 1.

FIGS. 2A-2C are photomicrographs of biopsies from one of the patients. FIG. 2A is a photomicrograph prior to treatment, and shows the bone marrow packed with leukemia cells. FIG. 2B is a photograph of bone marrow at day 14 of the induction cycle, showing elimination of leukemia cells, as expected, and additionally showing an unexpected and significant depletion of normal bone marrow cells. FIG. 2C shows the bone marrow at Day 28, showing no evidence of leukemia and restoration of normal bone marrow appearance and function.

The unexpected clearing of the marrow seen in the Day 14 marrow suggests that the increased remission rate observed in the current trial can be attributed to ODSH-mediated mobilization of leukemic cells from the marrow into the peripheral circulation, where they became vulnerable to the infusions of cytarabine and idarubicin. Retention of leukemic cells in the bone marrow is known to make them more resistant to chemotherapy (Hope et al., Nat. Immunol. 5:738-742 (2004)).

The recovery by Day 28 demonstrates further that the ODSH-mediated flushing of cells from the marrow does not adversely affect the ability of the marrow to repopulate and support multi-lineage hematopoiesis. Indeed, the accelerated recovery of platelet and white cell count, consistent with observations from a previous trial in pancreatic cancer, demonstrates that the marrow microenvironments required for thrombopoiesis, erythropoiesis, and granulopoiesis remain healthy.

6.3. Example 3: CX-01 ODSH Inhibits CXCL12 Binding to CXCR4

CXCL12, also known as Stromal Cell Derived Factor-1 or SDF-1, was originally described as a CXC chemokine produced locally within the bone marrow compartment to provide a homing signal for hematopoietic stem cells (“HSC”s). CXCL12 is the ligand for the CXCR4 receptor on the surface of HSCs; ligation of CXCR4 by CXCL12 is known to promote stem cell survival, proliferation, migration, and chemotaxis (see, e.g., Lapidot et al., Leukemia 16(10):1992-2003 (2002)). It has also been reported that the CXCR4 receptor is prominently expressed on the cell membrane of many cancer cells, particularly cancer stem cells (Yu et al., Gene 374:174-9 (2006); Cojoc et al., Oncotargets & Therapy 6:1347-1361(2013)), and that the CXCL12/CXCR4 interaction may mediate migration of cancer cells to anatomic sites that produce CXCL12 (Wald et al., Theranostics 3:26-33 (2013); Cojoc et al., supra).

To determine whether the ODSH-mediated mobilization of cells from the bone marrow observed in Example 2 was attributable to abrogation of or interference with the binding of CXCL12 to CXCR4, an in vitro inhibition assay was performed.

Polyvinyl 96-well high bind microplates (Corning Life Sciences, Corning, N.Y.) were coated with 0.5 μg/well of recombinant human CXCL12 (R&D Systems, Minneapolis, Minn.). Plates were incubated overnight at 4° C. and washed three times with PBS-0.05% Tween-20 (PBST). Separately, a constant amount of recombinant CXCR4 (Abnova, Taipei, Taiwan, 100 μL containing 0.8 μg/mL in PBST-0.1% BSA) was incubated with an equal volume of serially diluted ODSH (0.001-1,000 μg/mL in PBST-BSA) overnight at 4° C. The following day, 50 μL of CXCR4-ODSH mix was transferred to each respective CXCL12-coated well and incubated at 37° C. for 2 h. Wells were then washed four times with PB ST. To detect bound CXCR4, 50 μL of a mouse anti-human CXCR4 antibody (R&D Systems, Minneapolis, Minn.) (1 μg/mL, in PBST) was added to each well, the mixture was incubated for 1 h at room temperature, and the wells were washed again four times with PBST. Horse-radish peroxidase-conjugated secondary antibody (R&D Systems, Minneapolis, Minn.) (50 μL per well) was added, wells were incubated for 1 h at room temperature, and then washed once with PBST. A colorimetric reaction as initiated by addition of 50 μL of tetramethyl benzidine chromogen (TMB) single solution substrate (LifeTechnologies, Frederick, Md.) and terminated after 15 min by addition of 50 μL of 1N HCl. Absorbance at 450 nm was read using an automated microplate reader. IC₅₀ values were determined from the plot of absorbance values vs. concentrations of ODSH.

As shown in FIG. 4, ODSH inhibits binding of CXCL12 (SDF-1) to CXCR4 in a concentration-dependent fashion, with an IC₅₀ of 0.010 μg/ml. This inhibitory concentration is well within the range of plasma concentrations expected to have been achieved in the AML trial: as detailed in Example 2, patients were administered a bolus of 4 mg/kg followed by a continuous intravenous infusion at a dose of 0.25 mg/kg/hr for a total of 7 days; an earlier phase I study had demonstrated that a bolus of 8 mg/kg followed by continuous intravenous infusion of 0.64 to 1.39 mg/kg/h provides a maximum mean plasma level of about 170 μg/ml, and steady state concentrations of about 40 μg/mL (Rao et al., Am. J. Physiol. Cell Physiol. 299:C997-C110 (2010)).

Any heparin derivative that is capable of inhibiting, reducing, abrogating, or otherwise interfering with, the binding of CXCL12 to CXCR4, such as those capable of binding to CXCL12 and/or CXCR4 and preventing binding of CXCL12 to CXCR4, and that can safely be given at concentrations that reduce the binding of CXCL12 to CXCR4 without significant anticoagulation, should be useful in mobilizing cancer cells from bone marrow, and increase the effectiveness of chemotherapy in such cancers.

6.4. Example 4: Phase II Clinical Trial for the Treatment of MDS with CX-01 ODSH and Azacitidine

A pilot phase IIa study is conducted to confirm and quantify the therapeutic effect of adding CX-01 (2-O, 3-O-desulfated heparin derivative) to azacitidine in the treatment of recurrent or refractory myelodysplastic syndrome.

6.4.1. Primary Objective

The primary objective of the clinical study is to quantify the effect on complete response and near complete response rate (CR with incomplete count recovery) after combination therapy with CX-01 and azacitidine in patients with MDS.

6.4.2. Secondary Objectives

-   -   1. To quantify the partial response rate of combination therapy         with CX-01 and azacitidine in patients with MDS     -   2. To quantify event free, progression free, disease free,         1-year survival, and overall survival of patients treated with         CX-01 and azacitidine     -   3. To quantify hematologic improvement as determined by ANC,         platelet and RBC response     -   4. To characterize and quantify the cytogenetic response as         determined by reversion to normal karyotype

6.4.3. Overall Study Design and Plan Description

A pilot phase IIa, open-label trial is conducted to confirm safety and therapeutic effect of adding CX-01 to azacitidine in the treatment of recurrent or refractory myelodysplastic syndrome. CX-01 is administered as a 4 mg/kg bolus on Day 1 followed by a continuous intravenous infusion of 0.25 mg/kg/hr for Days 1 through 5 of each 28-day cycle. Azacitidine is administered at 75 mg/m² as a 15 minute intravenous infusion daily on Days 1 through 5 of each 28-day cycle.

Patients may continue treatment for up to 6 cycles or until they experience unacceptable toxicity that precludes further treatment, disease relapse or progression, and/or at the discretion of the investigator. Additional cycles may be administered after consultation with the Principle Investigator if a clear benefit is demonstrated for the patient.

A Data and Safety Monitoring Committee meets periodically to review the safety of the study. Adverse events (AEs) are collected from time of informed consent and continue until 30 days after last study treatment is administered.

6.4.4. Selection of Study Population

Inclusion Criteria:

To be eligible to participate in the study, patients must meet the following criteria:

-   -   1. Male or female, 18 years of age or older.     -   2. Diagnosis of myelodysplastic syndrome and one of the         following:         -   a. Symptomatic anemia with either hemoglobin <10.0 g/dL or             requiring RBC transfusion         -   b. Thrombocytopenia with a history of two or more platelet             counts <50,000/μL or a significant hemorrhage requiring             platelet transfusions         -   c. Neutropenia with two or more ANC <1,000/4,     -   3. IPSS score of INT-1 or higher at screening     -   4. Patient must have undergone ≥4 cycles of prior         hypomethylating agent (decitabine or azacitidine) without         response as defined by IWG criteria or have documented disease         progression after prior response to hypomethylating agent         therapy     -   5. ECOG performance status ≤2     -   6. >10% disease burden measured by cytomorphology, flow         cytometry, or cytogenetics     -   7. Peripheral white blood cell count <50,000/μL.     -   8. Total bilirubin <1.5×ULN; AST/ALT <2.5×ULN,     -   9. Creatinine <2.0×ULN     -   10. Must be able to understand and willing to sign an         IRB-approved written informed consent document.

Exclusion Criteria:

Patients who meet any of the following criteria are not eligible to participate in the study:

-   -   1. Treatment with any other investigational therapeutic agent         for the treatment of MDS within 7 days prior to study entry     -   2. Presence of significant active infection or congestive heart         failure that is not controlled in the opinion of the         Investigator     -   3. Presence of significant active bleeding     -   4. CNS leukemia     -   5. Positive HIV or hepatitis C serology     -   6. Known allergies, hypersensitivity, or intolerance to any form         of heparin     -   7. Patients receiving any form of anticoagulant therapy (heparin         flushes for IV catheter are permitted)     -   8. Psychiatric or neurologic conditions that could compromise         patient safety or compliance, or interfere with the ability to         give proper informed consent

Withdrawal and Discontinuation of Patients:

Patients are free to withdraw consent and/or discontinue participation in the study at any time, without prejudice to further treatment. A patient's participation in the study may also be discontinued at any time at the discretion of the Investigator or Sponsor.

The following may be justifiable reasons for the Investigator or Sponsor to discontinue a patient from treatment:

-   -   The patient was erroneously included in the study (i.e. was         found to be ineligible)     -   The patient experiences an intolerable or unacceptable AE     -   The patient is unable to comply with the requirements of the         protocol     -   The patient participates in another investigational study         without the prior written authorization of the Sponsor or its         designee     -   The patient's participation in the study presents a significant         safety concern.

Patients who experience Grade 4 increases in AST, ALT or bilirubin (e.g., increase in AST or ALT >20×ULN; increase in total bilirubin to >10×ULN) are discontinued from the study, if the Investigator judges that the laboratory abnormalities are potentially related to study treatment. Patients discontinued for this reason are not re-challenged and are followed until resolution of abnormal liver function tests. Patients who are discontinued from study due to an AE are closely monitored until the resolution or stabilization of the AE. Patients who received at least one dose of study drug and who are discontinued from treatment, but not withdrawn from the study, are asked to complete all evaluations for early termination (Early Termination/End of Study Visit). Patients who discontinue from the study are not replaced.

6.4.5. Treatment of Patients

6.4.5.1. Treatments Administered

CX-01 is administered as a 4 mg/kg bolus on Day 1 followed by a continuous intravenous infusion of 0.25 mg/kg/hr for Days 1 through 5 of each 28-day cycle. Azacitidine is administered at 75 mg/m² as a 15 minute intravenous infusion daily on Days 1 through 5 of each 28-day cycle. Patients may continue treatment for up to 6 cycles or until they experience unacceptable toxicity that precludes further treatment, disease relapse or progression, and/or at the discretion of the investigator. Additional cycles may be administered after consultation with the Principle Investigator if a clear benefit is demonstrated for the patient.

6.4.5.2. Dosing and Method of Administration

Azacitidine and CX-01 doses are calculated based on actual body weight at the beginning of therapy.

Preparation of CX-01 Infusion

The Investigator and pharmacist at the investigational site ensures Good Pharmacy Practices are followed during the preparation of the CX-01 IV solution. The volumes and CX-01 concentration in the final CX-01 IV solutions must be verified to be correct based on the patient's actual body weight measured at the beginning of the cycle.

Preparation of CX-01 Intravenous Bolus Dose

The pharmacist prepares the IV bolus resulting from the 4 mg/kg dose calculation with the amount of CX-01 from the appropriate number of 2 mL or 10 mL vials. Each 1 mL solution contains 50 mg CX-01 and must be further diluted in 0.9% sodium chloride. The calculated volume per patient (based on weight) is added to 30 mL of 0.9% sodium chloride solution and the total volume administered IV over 5 minutes.

Preparation of CX-01 Continuous Infusion Dose

The pharmacist prepares each study treatment solution, adding the calculated amounts of CX-01 and 0.9% sodium chloride to an empty, sterile infusion bag. An IV infusion line is then attached to the infusion bag, and the infusion set purged with the CX-01 solution. A Luer lock (or similar) is then placed at the end of the set. As CX-01 doses are weight based, the amount of CX-01 from the vials and saline solution both vary by patient's weight. Each 1 mL solution contains 50 mg CX-01.

For each continuous infusion bag, an appropriate volume and concentration of CX-01 solution is prepared such that the patient receives a continuous infusion at the dose of CX-01 of 0.25 mg/kg/hour. The final volume of the CX-01 infusion is 500 to 1000 millimeters/24 hours. The infusion bags are prepared at a calculated CX-01 concentration based on the patient's actual body weight.

Based upon current stability testing data, CX-01 infusion solutions expire at room temperature 72 hours after preparation and should be stored in a refrigerator (2 to 8° C.) until used.

If the IV infusion is interrupted for any reason, the time of infusion stop is recorded, along with the reason. The IV infusion is restarted as soon as possible, and the restart time recorded. The planned cycle days of treatment administration is not altered, nor is the concentration of the CX-01 solution adjusted, to compensate for an interrupted CX-01 infusion.

Azacitidine Dose Modifications

For patients with baseline (start of treatment) WBC ≥3.0×10⁹/L, ANC ≥1.5×10⁹/L, and platelets ≥75.0×10⁹/L, adjust the dose as follows, based on nadir counts for any given cycle:

Nadir Counts % Dose in the ANC (×10⁹/L) Platelets (×10⁹/L) Next Course <0.5 <25.0 50% 0.5-1.5 25.0-50.0 67% >1.5 >50.0 100% 

For patients whose baseline counts are WBC <3.0×10⁹/L, ANC<1.5×10⁹/L, or platelets <75.0×10⁹/L, dose adjustments should be based on nadir counts and bone marrow biopsy cellularity at the time of the nadir as noted below, unless there is clear improvement in differentiation (percentage of mature granulocytes is higher and ANC is higher than at onset of that course) at the time of the next cycle, in which case the dose of the current treatment should be continued.

Bone Marrow WBC or Platelet Biopsy Cellularity at Nadir Time of Nadir (%) % decrease in counts 30-60 15-30 <15 from baseline % Dose in the Next Course 50 − 75 > 75 100 50 33 75 50 33

If a nadir as defined in the table above has occurred, the next course of treatment should be given 28 days after the start of the preceding course, provided that both the WBC and the platelet counts are >25% above the nadir and rising. d, the next course of treatment should be given 28 days after the start of the preceding course, provided that both the WBC and the platelet counts are >25% above the nadir and rising. If a >25% increase above the nadir is not seen by day 28, counts should be reassessed every 7 days. If a 25% increase is not seen by day 42, then the patient should be treated with 50% of the scheduled dose.

CX-01 Dose Modifications

CX-01 is temporarily discontinued in patients who develops aPTT above 45 seconds during continuous infusion of CX-01 and at least 8 hours after the bolus dose of CX-01, until the aPTT is <35 seconds. CX-01 will then be resumed at a 50% dose reduction. If the aPTT rises above 45 seconds at the reduced dose, CX-01 is permanently discontinued. If aPTT at the 50% reduced dose is <35 seconds, 4 hours or more after dose reduction, the dose can be escalated by 25%. If the aPTT after dose escalation again rises above 45 seconds at the reduced dose, the CX-01 is temporarily discontinued until the aPTT is <35 seconds, and then resumed at the previous 50% dose reduction.

Permitted Concomitant Medications

The use of myelopoietic growth factors (G-CSF and GM-CSF) is allowed.

6.4.5.3. Response Criteria

Patients are assessed for response according to the IWG criteria:

Complete Remission (CR)—Defined as <5% myeloblasts with normal maturation of all cell lines in the bone marrow and peripheral blood values of Hgb>11 g/dL, Platelets >100×10⁹/L, Neutrophils >1.0×10/L, and 0% blasts. Persistent dysplasia does not exclude CR but will be noted.

Marrow Complete Response (Marrow CR)—Defined as <5% myeloblasts in the bone marrow and a decrease by >50% from pre-treatment values, but not meeting the definition of CR above.

Partial Remission (PR)—Defined as meeting the definition of CR above with a decrease of myeloblasts in the bone marrow by >50% from pre-treatment values, but absolute myeloblasts still >5%.

Stable Disease (SD)—Defined as not meeting the definitions of CR, Marrow CR, PR, SD, PD, or recurrence/morphologic relapse.

Progressive Disease/Relapse (PD)—Defined as ≥50% increase in blasts to >5% blasts (for patients with less than 5% blasts at baseline only), ≥50% increase to >10% blasts (for patients with 5-10% blasts at baseline only), ≥50% increase to >20% blasts (for patients with 10-20% blasts at baseline only), ≥50% increase to >30% blasts (for patients with 20-30% blasts at baseline only) or any of the following: At least 50% decrement from maximum remission/response in granulocytes or platelets, reduction in Hgb by ≥2 g/dL, or New or worsened transfusion dependence not related to study drug toxicity. Or for patients with a CR, Marrow CR, or PR as defined above and subsequently development of one of the following: Return to pre-treatment bone marrow blast percentage, decrement of ≥50% from maximum remission/response levels in granulocytes or platelets, or reduction in Hgb concentration by ≥1.5 g/dL or transfusion dependence.

Hematologic Improvement

Progressive disease as defined above nullifies hematologic improvement.

Erythroid response requires all of the following (only required if pre-treatment Hgb<11 g/dL):

-   -   Hgb increase by ≥1.5 g/dL     -   Relevant reduction of units of RBC transfusions by an absolute         number of at least 4 RBC transfusions/8 week compared with the         pre-treatment transfusion number in the previous 8 weeks. Only         RBC transfusions given for a Hgb of ≤9.0 g/dL pre-treatment will         count in the RBC transfusion response evaluation

Platelet response requires one of the following (only required if pre-treatment platelets <100×10⁹/L):

-   -   Absolute increase of ≥30×10⁹/L (for patients starting with         >20×10⁹/L platelets)     -   Increase from <20×10⁹/L to >20×10⁹/L and absolute increase >100%         (for patients starting with <20×10⁹/L)

Neutrophil response requires the following (only required if pre-treatment ANC <1.0×10⁹/L):

-   -   At least 100% increase and an absolute increase >0.5×10⁹/L

Cytogenetic Response

Cytogenic Response is defined as reversion to a normal karyotype. For this study, reversion of a normal karyotype is defined as no clonal abnormalities detected in a minimum of 20 mitotic cells. Progressive disease as defined above nullifies cytogenetic response.

6.4.6. Results

Addition of CX-01 ODSH, a CXCL12-interacting heparinoid, improves at least one of the above-described response criteria (see Section 5.4.5.3).

All publications, patents, patent applications and other documents cited in this application are hereby incorporated by reference in their entireties for all purposes to the same extent as if each individual publication, patent, patent application or other document were individually indicated to be incorporated by reference for all purposes.

While various specific embodiments have been illustrated and described, it will be appreciated that various changes can be made without departing from the spirit and scope of the invention(s). 

1. A method of treating cancer, comprising: adjunctively administering to a patient receiving an antineoplastic treatment regimen a CXCL12-interacting heparinoid, in an amount and at a time effective to enhance effectiveness of the antineoplastic treatment regimen. 2.-104. (canceled) 